


Blood Bond Over Blood

by Novastargeek



Category: Teenage Mutant Ninja Turtles (TV 2012), Teenage Mutant Ninja Turtles - All Media Types
Genre: Family, Fluff and Angst, Gen, Supernatural Elements, Tags May Change, Vampire Leo
Language: English
Status: In-Progress
Published: 2020-06-02
Updated: 2020-12-28
Packaged: 2021-03-04 04:47:04
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 10
Words: 22,726
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24507895
Author URL: https://archiveofourown.org/users/Novastargeek/pseuds/Novastargeek
Summary: A supernatural encounter in a museum warehouse leads to some unexpected changes in Leo. Good news is his family's always got his back. For better, or for worse.
Comments: 39
Kudos: 71





	1. Chapter 1

**Author's Note:**

> Hi! And welcome to my first fanfiction! This is an idea I've had rolling around in my head for awhile, so I decided to post it just to see what would happen. This takes place in the 2012 series towards the end of season 3.
> 
> Oh! Almost forgot the obligatory disclaimer: I don't own the TMNT, that honor belongs to Nickelodeon.
> 
> Anyways, onto the story!

The cool New York breeze playfully nipped at my blue mask-tails as I stood on the edge of one of the many run-down buildings that populated the old warehouse district. Despite the lullaby of angry horns and wailing sirens that echoed off the concrete jungle, it had been a quiet patrol.

“Mikey, I’m gonna beat the green off ya!” Raphael roared at a now squealing Michelangelo, who was currently sprinting to the nearest living shield. I turned a lazy eye to the growing hijinks behind me, half-continuing to pay attention to the alleyway below for non-existent activity.

The nearest living shield just so happened to be my genius younger brother Donatello. Who, based on the scowl that now adorned his features, was none too pleased to be stuck between the resident prankster and at the ticking time-bomb hothead.

“Donniiieeeee!” the youngest wailed. “You gotta protect me from the giant green hothead of doom and suffering! He’s gonna kiiiilllll meeeeeeee!”

“You decided to stick a cockroach down his shell, what did you think was gonna happen?” the sarcastic tone held a touch sharpness to it. An evil grin crossed his face as he suddenly side stepped, much to the shock of one sky-blue-eyed turtle.

“Donnie, what are you-“ whatever Mikey’s next words were cut off as a red and green blur suddenly tackled him to the ground.

“Noooooooo, how could my bestest brother in all the world betray, ow, OW!” Mikey’s questioning was cut short as his arm was brought back behind his shell, forced onto his carapace by a triumphant looking Raph.

He shot his best puppy eyes at his purple-masked brother, who, through no small feat, managed to ignore the pained baby brother looks part: “You lost all my sympathy the minute you threw that slime filled water balloon at me this morning.”

“Leo?” came the small, hopeful plea from my younger brother.

I looked at him and shrugged, struggling to keep my features schooled in my classic “leader” look. He got himself into this mess, he was perfectly capable of getting himself out.

“No Leo not you-OW!”

If possible, Donnie’s smile grew even bigger as he joined Raph in tormenting our baby brother. Said brother had begun to promise chores and his entire collection of comic books just to be spared from his “torture”.

I smiled at the scene, happy that all the different gangs and organizations shell-bent on world domination seemed to be taking a break for the moment. I didn’t even bother to try to quiet them down, Mikey and Raph especially needed an excuse to get rid of some of their pent up energy.

I turned my attention back to the sprawling warehouse district, prepared to call it an early night. Maybe pick up pizza, kick back, and watch a movie. Heaven knows we’ve earned it, between kicking the Krang out of New York, trying to save Karai, and that whole time traveling fiasco a few weeks ago.

I opened my mouth to call it a night when I saw a shadow out of the corner of my eye. It disappeared into the skylight of a warehouse kitty-corner to our current location.

I narrowed my eyes and sighed.

So much for a peaceful evening.

“Guys,” I called. The speed at which my brothers went from carefree, bickering teens to full alert ninja was a sight to behold.

Having my brothers full attention I continued.

“I think I saw someone head into that warehouse, through the skylight. It’s probably nothing, but just in case, we go inside, full ninja mode. Stay quiet, recon only.”

“Finally, some action!” Raph grinned from ear-hole to ear-hole. I just rolled my eyes and began heading over to the warehouse roof, my brothers right on my heels. We slipped into the same skylight I saw the figure vanish into, entering the building.

I motioned for my brothers to fan out and search the building for the intruder. They disappeared into the shadows, a well oiled machine, barely a whisper telling of their presence.

I leapt from rotting-wood rafter to rotting-wood rafter, scanning the ground below for any sign of an intruder. Just as I was about to give the all clear, I heard a muffled voice that was gradually starting to grow into a crescendo. I headed towards the sound, rewarded when I saw a black-hooded figure starting to tear through one of the boxes, clearly looking for something. Sawdust went everywhere, and several small, dark objects were scattered carelessly all over the floor. I hopped over to a beam positioned over the box. I leaned forward, hoping to get a better view and hopefully a clue as to what he was looking for.

I heard a loud crack, and instead of solid wood my feet stood on nothing but air. My hands flailed, trying to find something solid to hold onto, but they only found air. Sawdust flew everywhere, and I felt the air whoosh out of my lungs. Black spots danced in my vision. A hissing sound vaguely registered in my now ringing ears. I hazily felt something prick my neck, but was currently too focused on trying to force air back into my lungs to really pay any attention to it. Something hit my plastron with a dull thud.

I just laid there for a moment, greedily taking oxygen into my lungs and allowing my vision to clear and my ears to stop impersonating church bells.

My brothers were  _ never _ going to let me live this down.

“Leo, you okay?” I heard Donnie ask. I could feel more than see his eyes scanning me critically for any obvious injuries.

I groaned in response as I sat up, shaking my head clear of the cobwebs. I absently brought a hand to scratch at an itch on my neck.

“Hey hey hey, don’t scratch at it, you’ll only make it worse,” Donnie said as he pulled my hand away from the spot.

“Where are the others?” I asked as Donnie began to take care of the various cuts and scrapes that now littered my body.

“They went after the intruder,” the purple mask turtle replied, grabbing a penlight. “Now hold still for a sec.”

He shined the bright light in my eyes and I gave a small wince.

“Does your head hurt?”

“It’s a little foggy but otherwise fine.”

“You have a slight concussion, and I want to take a closer look at that bite when we get back to the lair.”

“Bite?” my brow furrowed in confusion. “I was bit?”

“When you fell into the box, the intruder was startled and apparently his first reaction was to bite you in the neck. Luckily, your entrance caused him to drop this staff he was looking for.”

He held up a three foot black-handled staff. Silver bat wings adorned the top of the staff, attached to a silver cage, the bars appearing to be fangs, sharp and wicked. But what drew my eyes was the deep, blood-red jewel that gleamed between the silver bars of its cage. It appeared to pulsate, slowly, a heart pumping blood to an invisible body. Deep red, intoxicating. A heartbeat. I needed it, inside me. A heartbeat. I needed-

“LEO!” Donnies shout tore me from my trance. “You OK? You zoned out for a minute there.”

“Yeah, I’m fine,” I shook my head, glancing at the staff and repressing a shutter as I pulled myself out of the box. “Let’s find the others and go home.”

I needed to get out of here. Put as much distance between myself and the staff as possible.

“No need to find us dudes, we’re already here,” Mikey wandered in, a fuming Raphael trailing behind him.

“He got away,” Raph reported punching his fist into his palm.

“Well, at least he wasn’t successful in his thieving endeavors,” Donnie replied, holding up the staff.

I felt my breathing quicken, and my heart began pounding in my chest. I turned away, facing the direction of the window we came through, fighting the urge to bolt out of the room as fast as I could. I didn’t want my brothers to think that their “fearless leader” was scared of a little stick. They’d never let me live it down.

“Woah, Dee, what is it?” Mikey asked, and I could imagine the wondrous “oh” shape he would be making with his mouth.

“Other than the fact that it’s obviously a staff of some kind,” he answered sarcastically, “I have no idea. There is a tag on it from the museum, so maybe if I look up the product number...”

He trailed off, and I was getting impatient. I need to get away. “Don, can’t you do this back at the lair?”

“Keep your shell on fearless,” Raph punched me on the arm. “It probably won’t take that long anyway. ‘Sides, if it was dangerous would you really want it just sitting in a warehouse for the next bad guy to waltz in and try to steal?”

I remained silent. I gave a slight nod of my head, knowing that he was right. That, that _ thing  _ was dangerous. Dangerous beyond belief. I couldn’t believe he didn’t know that, not with the way every instinct was screaming at me to  _ run _ . I crossed my arms and dug my fingers into them, trying to keep myself from having a full blown panic attack.

“You okay Fearless? You’re starting to shake pretty bad,” Raph suddenly asked, his voice full of concern. I hadn’t even realized. A headache suddenly decided to make itself known and I winced. Everything hurt, and the world was starting to spin.

“Leo? LEO!” Raph yelled.

Everything went black.


	2. Chapter 2

**Summary for the Chapter:**

> Leo passes out, and Donnie has to try to figure out why.

**Notes for the Chapter:**

> Hello again! Novastargeek here.
> 
> Welcome to chapter 2! I recently drew a cover for this story, and if you want to check it out you can find it under my Deviantart art account under the same name as my account here.
> 
> A huge thanks to all those who left a kudos or a bookmark, you made my week!
> 
> Anyways, obligatory disclaimer that I don't own TMNT.
> 
> Onto the story!

*DONNIE POV

“Aha!” I exclaimed as the results came up on my T-phone. It was quite simple really, I just had to hack into the museum mainframe, get past their rather pitfall firewalls, and viola! Type in the product number and all the information a turtle would need on a-

“Leo? LEO!” I heard Raph yell. My focus immediately shifted from my research to my red-clad brother, who was holding a passed-out Leo in his arms.

I ran over, my fingers wrapping around his wrist, searching for a pulse, relaxing a little when I found one there, though it was weaker than I would have liked. I brought my hand to his forehead, quickly pulling back when I felt the heat radiating off him in waves.

“Donnie is he gonna be okay?” Raph asked, biting his lip. “He was just standing there. He started shaking pretty bad before he just, fell over.”

“I don’t know Raph, but we need to get him back to the lab, NOW!” I ordered.

Mikey, meanwhile, I could feel shifting and pacing nervously, trying really hard to not break down into worried tears like he usually did anytime one of us could be seriously injured.

“Mikey?” I asked softly. His head turned up at the sound of his name. “Go on ahead of us to help Master Splinter get the lab ready.”

He gave a small smile, shooting off like a rocket, happy to do something to help. Really, any of my brothers got antsy when they were on the sidelines, but Mikey and Raph were always the worst in that regard. And as much as I wanted to prep the lab myself, I needed to stay here to monitor any changes to Leo’s condition.

“Raph, can you carry Leo?” I asked, and he gave a tight nod, bright green eyes tinged with worry, picking up our older brother in a bridal carry, cradling him close to his chest. Leo gave a soft moan as he was repositioned, but otherwise remained unconscious.

Without another word, we left the warehouse, headed for home.

The trip was made in a silence only broken by Leo’s occasional pained moans and our soft footfalls. Upon arriving at the lair, Raph deposited Leo onto the cot in our makeshift infirmary, which was set up in the far corner of my lab. Master Splinter placed a thin blanket on top of our brother, and planted a small, soft kiss on his forehead as Leo gave out a small whimper of pain. Mikey came in with a bowl of cool water and a towel, tears brimming in his baby blue eyes.

I took a blood sample while Raph and Mikey took turns keeping a white cloth on our eldest brother’s forehead. Master Splinter continued to murmur sweet nothings to Leo in Japanese, and once I declared my patient stable, he summoned Raph to give him a briefing of what exactly happened while we were on patrol in the dojo. Before he left, however, he placed another light kiss on Leo’s forehead, giving a soft smile when his son almost imperceptibly relaxed.

Leo continued to give low moans every so often, which Mikey matched with his own small whimpers and clicks of distress.

I gave a weary sigh, slipping further into “Doctor Don” mode. I hated seeing my brothers hurt, and I hated patching them up even more. Everytime one of us ended up on the bed, I was reminded that we weren’t as indestructible as we believed we were. I took another deep breath, further immersing myself in his blood pressure readings, soft erratic heartbeats, and gradually raising temperature, to distract myself, though the unfavorable readings made my brow knit tight with worry. People like my seemingly infallible big brother don’t just, just, fall over like a sack of potatoes. There had to be some sort of explanation, there just had to be.

I forced my emotions in, instead focusing my energies on forming a palpable theory. A slight concussion couldn’t have caused this, unless it was worse than I thought? No, all signs indicated slight concussion only, and I saw no signs of any major internal injuries that could cause the kind of trauma needed to make our fearless leader keel over. There had to be something, some clue, that I was missing, something-

A loud, hacking cough brought my train of thought to a screeching halt.

“Donnie?” Mikey’s voice pitched upwards. “Leo’s coughing up BLOOD! OH MY GOSH, HE’S DYING!”

Raph raced into the room at Mikey’s loud yell, eyes wide with panic, before masking over into a face of feigned hardness.

Mikey started breaking down into hysterics as I raced to the side of Leo’s cot, flipping him onto his side so he wouldn’t accidentally choke any of the blood.

Raph moved away from the body, pulling hysteric Mikey away from Leo’s cot to calm him down. A loud SLAP! echoed off the walls of the lab, followed by an indigent squawk of protest from Mikey.

“Leo’s not dying Mikey,” Raph said forcefully, before continuing on with an imperceptible air of hesitancy. “Right Don?”

I didn’t answer right away, looking at Leo’s mouth now that he had stopped coughing. There was certainly a lot of blood, but the heavy stream in front of his teeth indicated the blood was coming from his gums rather than from anywhere inside his body. Thank goodness. Although he had accidentally swallowed some of the blood, hence the coughing.

“Yes, Raph, he’s not dying,” I answered.

“See Mike? Leo’s gonna be just fine,” Raph gave a definitive nod, his shoulders slumping slightly with relief. Mikey let out a huge sigh of relief, though his eyes still traveled over Leo’s unconscious form with concern.

Then another round of coughing interrupted the moment. Small,  _ somethings _ flew out of Leo’s mouth along with the red liquid, hitting the floor with a light, dull clicking sound. Mikey promptly began freaking out again, and this time Raph just grabbed the edge of Mikey’s carapace and dragged him out of the lab. I’d have to remember to thank him later.

I turned my attention to the small red puddle on the floor. There were four small white objects sitting in the pool of blood. A closer inspection revealed them to be—teeth. Incisors, to be precise.

I began searching Leo’s mouth now that the coughing had once again subsided. The gap where his incisors once were was bleeding profusely, but upon further inspection I realized that something was  _ growing _ out of his mouth where his teeth used to be. And whatever it was was growing at an astonishingly fast rate.

Leo moaned as his new teeth began to grow in.

Instead of his previous incisors, something much sharper, curved, and more wicked looking grew in its place. It almost looked like…

Fangs.

Fangs.

Wait a second.

My eyes quickly scanned Leo’s neck for the bite mark I saw earlier. The bite didn’t have the uniform structure of a normal human jaw. It looked to be caused by a something with a mouth structure much closer to that of a predator, maybe some sort of large cat, a lion or a tiger, or a—

My mind whirring almost too fast to keep up, I pulled up the info on the staff we found in the warehouse:

The Bloodfang Staff is said to have once belonged to the legendary vampire, Dracula. Local legends claim the staff holds some of the power of a long dead and long lost love of Dracula’s, and has been claimed to have been used to control and ward off the supernatural creatures. The staff is on loan from the Transylvanian Historical Society for the temporary Legends of Halloween exhibit at the museum.

No.

This wasn’t scientifically possible, I mean, vampires don’t even exist, it’s just old legend and superstition, started by some half-crazy southeastern Europeans.

But, this couldn’t be more than just coincidence. I’d time traveled, survived several alien invasions, and was the product of glowing green ooze and ill timing trained in the ancient Japanese art of ninjutsu. So sure, vampires really shouldn’t seem like that much of a stretch.

Especially with all the evidence saying otherwise right in front of my face.

But, something in me just couldn’t believe it, wouldn’t believe it.

At least, not without proof.

And that meant experiments.

Experiments my older brother wasn’t conscious for and probably wouldn’t agree to right when he woke up.

I gave a great, big sigh at a loss for what to do.

Actually, you know who might be able to help?

_ Mikey. _

I gave an involuntary shudder at the thought.

But, with all the horror comics he reads, he might know exactly what abilities and side-effects of Leo’s condition we might need to test for, and how to deal with them.

Although, with how much he’s been freaking out in the last hour, it will probably take a while to convince him to get on board  _ without  _ him complaining about how Leo is a member of the undead.

Leo suddenly gave a small hiss, before curling in further on himself.

My attention turned back to my blue-clad brother with a long, weary sigh.

It was going to be a long night.


	3. Chapter 3

**Summary for the Chapter:**

> Leo wakes up, and things don't go so well.

**Notes for the Chapter:**

> Salutations, readers!
> 
> Three chapters in and I'm still shook that people are reading this little story of mine. Special thanks to those who have left a kudos or bookmarked so far!
> 
> In other news, Nick owns TMNT, and I, alas, do not.
> 
> Onto the story!

*LEO POV

Everything hurt.

I was exhausted, and wanted nothing more than to sink back into the peaceful blackness, where the hurt faded away. Some unexplained force, however, had other ideas, and I found myself climbing back to wakefulness regardless of my body's pleas to shut back down.

I tried to open my eyes, but they were just too heavy. So, I settled on using my other senses to figure out where I was.

The gentle whirring of machines told me I'd somehow ended up in a lab. Maybe Donnie's? Though I couldn't entirely recall why. I racked my brain, trying to figure out what happened before I ended up here. I was rewarded with a splitting headache and a disappointing lack of answers.

I wanted to fall back asleep, but the little nagging feeling grew more persistent, and forced my brain to function even though my body didn't want to.

It took a tremendous amount of effort, but I managed to lift my lead eyelids with a groan.

However, the little bit of light that entered through my half-lidded eyes seemed to burn them so painfully I quickly squeezed them shut again.

"'onnie?" I slurred. Something in my mouth felt kinda weird, and very, very wrong.

"Leo, oh thank goodness you're awake!" he exclaimed, and while his voice seemed kinda far away, his heavy footfalls seemed to pound within my aching skull.

"'onnie?" I tried again, still slurring. "Wha' happ'n?"

I tried to sit up, make sure my brother was okay, but aching muscles and a hand gently pushing on my plastron forced me to stay down.

"Just rest Leo," Donnie said softly. "You've had a rough twelve hours."

Twelve hours? I was either injured or sick, then. The pain, well, everywhere indicated the former.

I wanted to ask what happened again, but exhaustion finally won out and I was dragged back into sleep once more.

*)><(*

The next time I woke up, I was in significantly less pain, though I was still sore. Particularly in my mouth, behind my eyes, and just generally everywhere in my head.

I tried opening my eyes again, but the searing light made a painful return, forcing them shut again.

The speckled grey behind my eyelids suddenly became darker, so I decided to risk opening my eyes again. I was greeted with no searing pain, though I still had a nasty headache and I saw the slightly scorched ceiling of Don's lab and my purple-banded brother's gapped-tooth smile.

"Morning Leo," he softly greeted.

Mikey's bright smile filled my vision as Donnie stepped aside.

"Or should we say good evening!" Mikey giggled, voice surprisingly matching the soft tamber of Donnie's greeting, for which I was very grateful. Even my brother's soft voices seemed way too loud, almost melting into the too loud beep of the heart monitor next me and the normally soft whirring of Donnie's machines.

The sudden smell of anesthetics and dried blood assaulted my nostrils, mixing with the smell of motor oil and sweat and _relief_ and, _fear_ , radiating off my brothers in waves. I felt the bile rising in the back of my throat, and I swallowed it down before it had a chance to escape my body.

I heard footsteps as Mikey helped me to sit up. Raph stood at the edge of the bed, smirking slightly.

"Good to see you in the land of the living Fearless," Raph gruffly greeted.

"Good to be back," I responded, giving my brothers a small smile, said brothers flinching slightly. The smile quickly turned into a frown. My jaw was extremely sore, and something felt, _off_ in my mouth. I ran my tongue across the back of my teeth. I felt something long and sharp protruding from my gums. I froze. My heartbeat roared in my ears, and suddenly I found I couldn't breathe, because there was something in my mouth and that wasn't supposed to _be_ there-

"Leo, deep breaths bro, common, breathe with me," Donnie's calm voice cut through the raging storm of panic that had come from out of nowhere.

"Donnie?" I asked, once I had my breathing back under control. "My mouth feels kinda weird."

"How exactly?" Donnie raised his eye-ridge.

"My gums feel sore, and there are these, weird, long, sharp, _things_ in my mouth."

I run my tongue across the back of my teeth, again, slowing down when I reach the part that didn't feel quite right.

"They kind of feel like fangs?" I question hesitantly. Honestly, that was the closest comparison I could get, especially without a mirror.

Donnie gave me this _look_ before he answered me, the look he normally gets when we get injured and he doesn't want to tell us how bad it really is.

"That's because they are, Leo."

My mind stopped working again.

What. The. Shell.

Were _fangs_. Doing.

_In my mouth_.

I was a turtle, and last I checked, turtles didn't have fangs. It was anatomically impossible for me to just suddenly develop fangs. Maybe it was a classic Mikey prank, and he found some fake teeth and decided it would make a good prank. And decided to rope my brothers into it. Though he had poor timing and should have known better, and at least Donnie should have had enough sense to stop him. The more I thought about it, the more convinced I became of the possibility.

"Okay, Mikey, very funny," I said, reaching my hand in my mouth to try to pull out the fake teeth, wincing a little when the light tugging aggravated my already sore gums. He must have used extra strength glue or something, then. "Sticking fake fangs in my mouth is, one, not a very good prank, unless you wanted to convince me I was some sort of vampire or something, and two, is a not the best way to get a laugh when I'm already disoriented enough as it is."

"I'm not laughing dude," Mikey frowned. "I haven't pulled a single prank since we brought you back."

"Mikey," Raph growled from his place at the foot of the bed.

"Okay, I haven't pulled a single prank on _you_ since we got back."

I raised an eye-ridge.

"Seriously dude, turtle's honor," he held up a three fingered hand. I searched his face, and became more concerned when I saw nothing but honest concern with a hint of confusion.

"Though, your accusation wasn't entirely wrong," he commented offhandedly.

Now it was my turn to be confused. If he hadn't pranked me, then no part of my accusation would be accurate. I looked at my brothers, and Raph and Donnie's eyes were aggressively boring into Mikey's entire being.

"What, he basically figured out he's a vampire on his own, I was just giving him a little helping hand," Mikey rubbed the back of his neck and gave them an innocent smile.

Being a _vampire_ was not what I thought was right about that statement.

I felt my mind freeze. My hand went back to my mouth, this time gently feeling the four, new, sharp additions to my mouth. I felt for the hard line that I was so sure excited only minutes ago that would indicate false teeth, and was disappointed when I found none.

"Can I please have a mirror," I asked, starting anywhere but where my brothers were. "I need to see them."

"Why, you won't be able to see yourself anyway," Mikey states.

"Humor me then, please?" I practically beg.

I heard Donnie shuffle over to one of the supply cabinets, before rummaging around and shuffling back over and handing me the blue plastic mirror. I held it up, only to see the cracked wall of the lab behind me.

I gave a frown and tried moving it. Maybe I was still a little out of it from my concussion. I wave a hand in front of the mirror. Nothing.

It's like I wasn't even there, like I was a ghost or something. Maybe it still was an elaborate prank of some sort. I look up, searching my brother's faces for any signs of barely held back laughter or a joking gleam. I only found wide-eyed concern and, was that _pity_? Or just sympathy? I really hope it's just sympathy.

"Why can't I see myself?" I asked, staring back at the wall in the mirror. Donnie moved next to me, and I saw his reflection join the wall. But mine was still strangely absent.

I stared up at Donnie, pleading with my eyes for him to give me an answer. He's a scientist, right? He _has_ to have an answer. He _has_ to.

"That confirms it," Donnie announced. His mouth morphed into a hard line, and he has this air of finality to him, the same one he gets when he discovers a broken bone or some internal injury that will keep us bed-ridden for weeks.

Raph's face imperceptibly fell, and he hesitantly started rubbing my leg in a rare comforting gesture.

"Confirms what, Donnie?" I asked, not really wanting to confirm the rapid conclusion my mind was coming to.

"Do you remember how I said you were bit?" Donnie started after a moment of silence. I gave a silent nod, my free hand subconsciously going to the spot on my neck.

"It turns out the guy that bit you wasn't actually human," my purple-clad brother continued. "He was a vampire. And when a vampire bites a non-vampire…"

He trailed off, and just like that all the pieces fell into place. The way everything seemed just too bright and too loud, the myriad of new, strange, almost nauseating smells assaulting my nostrils, the lack of a reflection. The, _fangs_.

Mikey grabbed my free hand and started rubbing circles on the back of it.

I could feel the cool plastic handle of the mirror being pulled out of my hand as my throat constricted and I could no longer pull air into my lungs.

I became aware of a roaring heartbeat.

Beats.

My heartbeat.

Circulating lifeblood through the body.

I felt a pulse in my right hand.

A gentle squeeze.

Grounding.

Breathe.

Bum.

Ba bum.

Ba bum.

Pounding.

Pulsing.

Another.

Thick.

Rich.

Hunger.

Thirst.

Ba bum.

Ba bum.

Ba bum.

A prick, then silence.


	4. Chapter 4

**Summary for the Chapter:**

> Leo tries to come to terms with what happened in the last twenty-four hours.

**Notes for the Chapter:**

> Greetings and Salutations!
> 
> Welcome back to my story, and I'm super glad to hear people are actually enjoying this. I'd like to give a big hearty thank you to anyone who has left a kudos/bookmarked this story so far!
> 
> Also, special thanks to KatWithTheGlasses for leaving the first comment!
> 
> There is minor use of Japanese this chapter (and future chapters), and translations can be found at the bottom.
> 
> As always, Nick owns TMNT, and I do not.
> 
> Onto the story!

*LEO POV

I hoped and prayed that the last twenty-four hours were some kind of nightmare as I once again regained consciousness from another forced slumber.

I ran my tongue across the back of my teeth, disappointed to find that it wasn't. There were still four abnormally sharp teeth sitting in my mouth, threatening to nick the inside of my mouth as I gently stretched my aching jaw.

I opened my eyes to find Donnie giving me a look that was a mixture of concern and relief as I sat up: "Are you good now, Leo?"

Physically, yes, I seemed okay. A little sore, but fine nonetheless.

Mentally? Emotionally?

No, no I was not.

"Yeah, I think so," I replied anyway, proud that my voice only shook a little. Although the slight lisp was new. As if my voice hasn't changed enough in the past few months.

Donnie's face relaxed ever so slightly, and he gave an almost inaudible sigh of relief.

"Ok," Donnie began to slip into Doctor Don mode. "If you're feeling up to it, I want to run a few tests."

He looks me in the eyes, penlight in hand, and it's then that I realized just how exhausted he looked. Large bags were visible under his eyes, which themselves were bloodshot. The bitter smell of coffee hung off him like a cloud. He hunched over slightly, and I could hear the sluggish rhythm of his heart. He stifled a yawn behind his hand.

"Which you can run after you've gotten a good night's sleep," I gently scolded him. He gave me an unimpressed look.

"Leo, I'm not that tired," he lightly whined. "And you and I both know I've stayed awake much longer than this."

"And we both know how not healthy that is," I countered.

"These tests are important, Leo," he tried again. "I need to know how these new changes exactly affect your physiology and to what to degree so that-"

"I'm sure they're important, but I'm also sure they can wait until you've allowed yourself to rest. My physiology isn't going anywhere."

"But I did sleep, not that long ago."

"Donnie, I'm almost suffocating in the coffee smell on you and can hear you trying to hide a yawn about every five seconds."

He opened his mouth to protest but ended up yawning instead.

"When was the last time you slept, _otōto_?"

"I, uh," he stuttered.

I raised an eye-ridge.

Donnie at least had the decency to look ashamed as he mumbled something my ear-slits caught as thirty-six hours ago.

"Once you've slept, you can run all the tests you want on me, okay?"

He gave a small nod as I slipped off the cot, blinking away the brief dizzy spell that came from the action. I put a hand on his shell and gently guided him out of the lab and towards his bedroom. As soon as his gear was off, Donnie flopped onto his bed, his breaths instantly becoming deep and even.

"Sleep well, _otōto_ ," I whispered, pulling the covers up to his chin. He started to snore and a little drool dribbled from his mouth onto the pillow. I chuckled at the adorable sight as I went to shut the light off, only to find that it already was. I could've sworn I hit the switch on the way in, especially with the amount of small details I saw in the room. I shrugged it off as I shut the door, chalking it up to another side-effect of my, _condition_.

I still felt too awake to even try to sleep, so I debated several options to occupy my time. TV was out of the question with how dialed up my senses seemed, and I didn't want to risk waking up anyone else in the lair, knowing they needed the sleep after the excitement of the last few days. I thought about meditation, but I had been still for almost a whole day, and the lack of motion required to meditate properly was unappealing at the moment. My muscles felt a little weak after lying down on a bed for so long, and the excess energy I had could easily be depleted by some light training.

Decision made, I headed over to the dojo and began to run through some basic katas, being sure to keep my movements as silent as possible. I felt the lethargic soreness in my muscles fade as my sword sliced through the air, cutting through hoards of invisible enemies.

I fell into a comfortable rhythm, and my thoughts began to drift and time disappeared as I flowed from one form to the next. I still couldn't believe I'd been bitten by a, _vampire_ , of all things. I guess it probably shouldn't have been that hard to believe, given the kind of lives we lead, but for some reason, the thought refused to sit in my brain. Some small part of me still held onto the whole "elaborate prank" idea, however much my brother's reactions dispelled the notion.

"My son, why are you training at this hour?" Sensei announced as he entered the dojo.

I was so caught up in my thoughts that his sudden presence caused me to jump. My fangs cut the underside of my mouth as I gave a small yelp of surprise-turned-pain.

Blood rapidly flowed from the small cuts, and I reflexively started sucking before it had a chance to dribble out of my mouth. I held the red liquid in my over my tongue, and my eyes shot open wide as I realized that the normally repulsive metallic tang was actually the _best thing_ I have _ever tasted_ in my _entire life._

"Leonardo?" Sensei called softly.

I froze, sucking becoming more rapid as I closed my eyes in pure bliss, barely registering that my swords had clattered onto the floor. I gave a small hum of contentment as the slightly salty liquid danced across my tongue.

All too soon the two small wells dried up. I was disappointed —and seriously tempted to reopen the wound with my fangs —but I knew Donnie would have my shell if I injured myself for just a small moment of contentment. But, maybe I didn't _have_ to hurt myself in order to enjoy the red gold again...

As soon as the thought crossed my mind, it was replaced with another that expressed horror at what I'd just done.

"My son, are you alright?" Sensei asked from behind me.

Shame wells up in my gut, and I hang my head, not wanting to face my father after, after I'd...

At the same time, every hope I had of this whole situation being hoax or some horrible nightmare faded and the crushing weight of reality settled onto my shoulders and made my heart clench.

"I," I started, "I just, just-"

His silence encouraged me to take as much time as I needed to find the right words.

I took several large, deep breaths before continuing.

"I tasted blood, Sensei."

"And how is that unusual, my son?"

Another pregnant pause.

"Leonardo?"

He should know, right? I know he was a little out of touch with modern culture but even _Sensei_ should know the connection between vampires and blood. It was Halloween lore 101, for crying out loud! I whirled around, looking him dead in the eyes.

"I _liked_ it Sensei!" I yelled. Once I started, I couldn't stop, the words pouring out of my mouth in a rush. "I'm a _vampire_ and I just _drank blood_. And the worst part was _I liked it_. It tasted like heaven on earth and I was just, so _happy_ that there was _blood_ in my _mouth_ and when it was gone I wanted more and _I still want more_ and I didn't want to hurt myself more so I started _scenting_ for other sources and I found four and they're _you_ and _my brothers_ and oh _shell, what if I actually do it and-_ "

I felt two strong, furry arms wrapped around my carapace, pulling me into a hug and silencing my panicked rambling. Sensei began murmuring comforting Japanese nothings into my ear. I noticed that my mask felt strangely wet.

"It is alright to cry, my son," Sensei said as I choked back a sob. "You have been through much in the past day. If you do not let it out, it will build until it explodes again. And you will likely cause great amounts of harm to those around you. I do not believe your tears to be a sign of weakness, _musuko_."

At his words, the dam broke, and I buried my head into his chest, allowing sobs to wrack my body. He continued to hold me, rubbing calming circles on my shell and softly humming a Japanese lullaby.

Eventually, the sobs turn to sniffles and my tears run dry. I slump against my father, all of my previous energy completely spent by the breakdown.

"Change, especially change as sudden as yours, is absolutely terrifying," my father speaks into the quiet. "And many of these changes will not initially feel welcome."

I look at him, my face twisting in confusion. It sounded like he was speaking from personal experience, but when would he have-

Oh.

_Oh_.

"But, I find that focusing on and allowing your family to help can make the transition easier and the uncomfortable changes more bearable."

The unspoken invitation to talk hangs in the air, but I was too emotionally drained to take advantage of it, so I filed away the advice for later.

My father, sensing my exhaustion, resumed his soft humming, and my head fell back against his chest. My eyes closed and I fell asleep, comforted by the soft beating of my father's heart.

**Notes for the Chapter:**

> Otōto- Little Brother
> 
> Musuko- Son


	5. Chapter 5

**Summary for the Chapter:**

> Leo has sensitive senses and Donnie prepares some, interesting experiments.

**Notes for the Chapter:**

> Greetings and salutations!
> 
> Welcome to chapter of five! Before we dive in, I'd like to once again extend a huge thank you to everyone who has left a kudos, bookmarked, or commented on this story so far. I always get a huge smile on my face whenever I see that people are actually enjoying this crazy thing!
> 
> The Japanese is brought to you by Google Translate-so if anything looks off please don't hesitate to correct it if it's wrong-and translations can be found at the bottom of the page.
> 
> As always, Nick owns the turtles, and I don't.
> 
> Onto the story!

I woke up after a very peaceful sleep, feeling refreshed for the first time in days. Even the still foreign-feeling fangs and the constant onslaught of sensory information I was receiving did nothing to hamper my good mood.

Speaking of senses, for the first time I registered just how _sensitive_ mine had become. While I was trained to operate in low-light conditions, I can't recall ever being able to see the almost disorienting amount of color and detail I could see in what I knew was a near-dark room.

The normally dulled whooping and laughter as Mikey and Raph played video games in the common room now slammed against my ear-slits. If I focused past their cacophony, I could hear the muted clinks mutterings coming through the supposedly soundproof door to Donnie's lab. He must have cracked open the door for some reason or another. With a slight frown I realized I couldn't hear Sensei at all. Perhaps he was meditating in his room, away from the commotion in the common room.

I quickly identified the nausea rising in my stomach as a byproduct of the myriad of unpleasant scents that drifted in from the sewers through the abandoned subway tunnel. But, if I closed my eyes and focused, I discovered I could identify the much pleasanter scents of my family members.

Mikey's hit me first, a combination of days-old pizza and latex from all the water balloons he was always pranking us with. Raph's musk of sweat and smog was next, a byproduct of all the time he spent topside. I realized that, yes, the door was open in the lab, as Donnie's scent drifted in, an unsurprising mix of chemicals and motor oil. I tried to find any hint of Sensei, but again I came up empty. I concentrated harder, allowing my nostrils to flare, and, there! I found a faint trail of incense and fur that bled into the subway tunnel. He had left the lair hours ago, if I was smelling correctly, though I had no idea why he would do so, especially considering what happened in the dojo earlier this morning.

With a start I glanced at the small digital clock on my nightstand. The glowing blue numbers read 6:57 pm, roughly thirteen hours hours after I'd finally fallen asleep.

Turns out I had slept through the whole day.

Huh.

I shook it off and started putting my gear on, beginning with my well-loved blue mask. I then proceeded to put on my sports tape, knee and elbow pads, and finally my belt and straps for my katanas, which I left hanging on my wall. I knew I wouldn't be patrolling tonight —or probably the rest of the week, for that matter —but it never hurt to be prepared.

I left my room, then promptly headed back in once I was assaulted by just how much _brighter_ and _louder_ and _nauseating_ everything was out of the quiet dark of my room. I scrounged my meager positions for anything that could possibly block out even a small amount of the sensory overload I was receiving. The only thing I could find was my blue comforter, which I wrapped around my head and shoulders a few times like a hooded cloak.

I winced as I exited the room, disappointed that the blanket didn't really do much beyond being a not-so-fashionable accessory.

I got annoyed as I became aware of a rapidly growing headache that had started forming, _everywhere_ in my head.

"Morning Leo!" Mikey chirped as I entered the common room, looking up from the game with a bright smile. "Or should I say good evening?"

His face scrunched up, contemplating the proper greeting.

"Glad to see you awake sleeping beauty," Raph gave me a slight smirk, though the tension in his shoulders betrayed his worry. Probably over me. The big softie.

"Good to be awake," I smiled back, being careful to not show my fangs after the reactions my brothers had in the lab after the second time I woke up.

"How are you feeling, bro?" Raph asked, pausing the game and setting his controller down. My headache lessened slightly at sudden lack of loud noises and bright sounds from the TV.

"Fine," I muttered, prompting a raised eye-ridge from my hothead brother.

"I've been better," I revised with a sigh. I sat on the bench-turned-couch, massaging my temples in a failed attempt to dispel the pounding in my skull.

Raph chose not to pry further, which I was thankful for. Mikey suddenly bolted up from the couch, making a beeline for the light switch. He shut off all the lights except one by the turnstile entrance to the lair.

"Thanks Mikey," I said as my headache receded further.

"No problem, bro!" he flashed me a bright smile. "Oh! You must be starving dude. I know! I'll make you some of my famous breakfast pizza!"

I wasn't really all that hungry, but his sheer enthusiasm kept me from voicing my objections.

Mikey raced towards the kitchen, abruptly coming to a complete halt halfway there, his smile morphing into a light frown.

"Can you let Donnie know Leo's awake as long as you're up?" Raph asked lazily from his comfortable position on the couch.

"Yeah, sure bro," Mikey replied distractedly as he changed direction and headed for the lab instead.

He slipped into the lab, and the two started talking too low for me to make out what they were saying.

"What got under his shell?" Raph commented as he gave a curious eye to the lab door. We both wondered what could have caused such a dramatic flip in Mikey's normally cheery demeanor.

"THANKS DEE YOUR THE BEST!" he yelled a few minutes later—unfortunately back to normal—as my hands flew to my ear-slits on reflex, eyes squeezing shut. Mikey ran out of the lab and headed straight to the kitchen.

"Any louder and they'll hear him in Jersey," Raph complained next to me, thankfully at a much preferable decibel level.

"I think they did hear him in Jersey," I complained back with a wince.

There was a crash from the kitchen and a loud "I'M OKAY!" from Mikey, which caused a small hiss of pain to slip through my teeth. Both of us then gave a slight chuckle in fond exasperation at our youngest brother's antics.

Donnie exited his lab a moment later, his med-box in his right hand and a notebook in his left, giving me a tired smile.

"Sorry about the noise," he apologized. "Any new symptoms or weird feelings I should know about?"

Raph scooched over as Donnie set the items on the couch and kneeled in front of me.

"Just a massive headache and a little nausea," I told him, deciding —for once —to be honest about my symptoms. "The headache got better once Mikey shut the lights off and got way worse when he decided to start shouting loud enough for Jersey to hear."

Donnie gave a small chuckle the comment.

"Over-stimulation," he said after a long moment of concentration. "As you are probably well aware, your senses have all increased their sensitivity as a result of your, _condition_ , and your brain just doesn't know how to process all the new information yet. Your senses will regulate the more you allow yourself to operate as you did before the, _incident_. That being said, I'll allow the lights to be off and we'll all try to keep the volume low tonight, but tomorrow the lair will be back to business as usual, and I expect you to be present in it, no matter how much you will want to hide in your all day. Theoretically, your senses should re-regulate themselves within the next three to five days."

"Great, a few more days of _this_ ," I said, burrowing further underneath my blanket.

"But after that, you'll be better than new!" Donnie replied, far too chipper and happy at his announcement. I rolled my eyes as he started rummaging around in his med-box.

He coaxed me out of my blanket, and began his examination by pulling out a thermometer and sticking it in my mouth. After that, he pulled out a stethoscope and had me take a few deep breaths, listening to my heart and lungs. Donnie continued with several smaller tests, including an extensive examination of my ear slits and a long inspection of my mouth and jaw. After each test he would jot a few words down in his notebook, muttering a bunch of sciencey words I didn't understand. I gave a small hiss when my headache flared after he shoved a penlight in my right eye, then my left.

Raph, meanwhile, had begun quietly flipping through channels on the TV, keeping the volume blessedly low, finally settling on a rerun of _Space Heroes_. I felt touched by the surprisingly thoughtful choice of programming.

"Leo, I'm happy to report that you're a fine specimen of turtle health," Donnie announced, standing up. "At least considering all the changes you've gone through in the past day and half. If you feel up to it, I'd like to run some more extensive tests in the dojo to see exactly what, uh, vampires qualities you've acquired, beyond the heightened senses and those fangs."

He gave me an awkward smile, and despite how terrible I was feeling—and how much I wanted to avoid anything to do with this whole situation—I decided that it would be better to get these tests done as soon as possible.

"How much time do you need to get everything set up?" I asked.

"Ten minutes," he replied.

"Perfect," I said. "That will allow me enough time to finish waking up."

Donnie gave me a nod and departed to his lab to start getting everything ready.

As soon as my scientist brother left the room, I felt the muscular arms of my red-clad brother wrap around me in a crushing death hug, as if I was going to float away at any second.

I sat still in complete shock, before hesitantly wrapping my arms around my younger brother's carapace. Neither of us said anything as I held my brother for a surprisingly long period of time. Almost a whole minute, by my calculations.

" _Daijōbu, otōto_?" I asked as we pulled apart.

He stared at me for another long minute with this _look,_ the same one he gave my in the days after...

After I woke up from my three-month long coma.

" _Hai, aniki. Daijōbudesu_ ," (Yes, big brother. I'm fine)giving me a small, _genuine_ smile. Just as quickly as it appeared, however, it was gone.

"If anybody asks, this never happened," he said pointedly, rising for his seat and heading into the dojo.

I stared after him, contemplating the weird show of affection. I would expect a display like that from Mikey, but Raph?

I shook my head—which I quickly realized was a horrible idea —as I filed away the incident for later, followed after my younger brother.

Soft light filled the space courtesy of the candles that he had started lighting all around the dojo. I voiced my thanks as I took a seat underneath the large tree that rose from the dojo floor. Closing my eyes, I took a large, deep breath, finding my center. I instinctively began to categorize the sounds and smells that flooded the appropriate senses, and quickly discovered that focusing on one sound or scent at a time helped to reduce the pounding in my skull to a dull throb.

Soft footsteps and the gentle clanging of who-knows-what inside a large, cardboard box indicated the arrival of my genius brother. I lazily cracked my eyes open, and watched Donnie start pulling objects out of the box, setting them neatly on the floor. I closed my eyes again, enjoying the slight reprieve from my headache.

"Geez, have enough stuff there Donnie?" Raph commented sarcastically from the other side of the dojo.

Donnie just ignored him, and continued to place each object on the floor with a soft thud. I refocused on identifying the scents of my brothers, before realizing that one very important scent was still missing from the lair. I opened my eyes again, watching Donnie finger a silver dog whistle.

"You know how much that bothers Master Splinter, right?" I asked Donnie, eye-ridge raised. Donnie gave a small hum in acknowledgement.

"Speaking of which, where is Sensei? I picked up his trail this morning, but it was faint and led out of the lair."

"I asked Splinter to leave for the evening," he informed me nonchalantly. "Just as a safety precaution, as some of the experiments Mikey and I planned will bother those with sensitive senses."

The statement contained several suggestions that did nothing to ease my now rising concern for these, _tests_.

I re-closed my eyes, focusing on my breathing as I slipped into a light, meditative trance.

Out of nowhere, a high pitch whine pierced the air, loud and draining and painful and just make it _stop please make it_ -

I took a deep breath as Donnie removed the accursed whistle from his mouth, muttering and scribbling something down in his notebook. My headache came back full force, and I uncurled myself from the ball I turned into at some point during the awful sound.

"What was that for?" Raph exploded for the both of us, whirling to face Donnie. My ears-slits were still ringing and hurting too much to do anything more than glare in my purple-banded brother's direction.

"You know how much Leo likes to hide his pain levels from us," Donnie answered back, giving me a look that was two parts frustrated and one part apologetic. "Surprise tests are the only way I can ensure I get accurate reactions and measurements to the way outside stimuli physically affect our brother. Sorry Leo."

Raph mumbled some choice words under his breath, and for once I didn't bother calling him out on his language.

"S'okay," I murmured back as the pain finally began to reside. "Just please don't do it again."

Donnie gave a nervous laugh.

"Sorry Leo," he apologized with a strained smile.

I gave a small hiss in irritation, resigning myself to a night of pain and torture at the hands of my scientist brother.

**Notes for the Chapter:**

> Daijōbu, otōto?- Are you okay, little brother?
> 
> Hai, aniki. Daijōbudesu.- Yes, big brother. I'm fine.


	6. Chapter 6

**Summary for the Chapter:**

> Leo's powers don't just show up by themselves. Hence, experiments.

**Notes for the Chapter:**

> Hello and welcome!
> 
> Just a heads up that the next few updates might be a little wonky, as real life is just a little on the crazy side right now.
> 
> Once again, a huge thank you to all who have left a kudos, bookmarked, and commented on this story so far! Seeing your support really brightens my day!
> 
> For the sixth week running, I still don't own TMNT, but Nick does.
> 
> Onto the story!

*LEO POV

The night wasn't all pain and torture.

After the very, _very_ annoying dog whistle, Donnie played a long, low tone though a speaker that was the audio equivalent of dunking my throbbing ear-drums in blessedly cool water. At Raph's look of confusion, my genius brother explained that he was playing a tone that was far too low for them to hear. I gave a small hum in contentment and approval as the tone reverberated throughout the dojo.

The gentle scraping of graphite on paper was almost grating in comparison to the wonderful noise.

"Alright, I'm going to start lowering the frequency," Donnie instructed, "Raise your hand when you can no longer hear the sound. After that, we're going to do the same thing on the opposite end of the spectrum. And though I promise I won't use the dog whistle again, I can't promise it won't, cause some discomfort."

I gave a small nod, relishing the last moments of low tone as it faded away into nothing. I raised my right hand, and the sound began to rise in pitch until it was just as painful as the dog whistle. I winced, but the sound eventually, thankfully, dissipated. My right hand rose up, and once again Donnie jotted down the numbers in his notebook. To my surprise, the low tone began to thrum anew in the room.

I hummed a thank you, accepting the wordless apology from my scientist brother. Said brother taped one of those seeing eye charts with the big "E" on top onto Sensei's door. He instructed me to stand on the opposite end of the dojo and read the lines out loud. I easily did so, and when I was finished, Donnie ordered Ralph to blow out all the candles, and I repeated the test in the near-dark, with the exact same results. Raph grumbled as he was forced to relight all the candles.

"Hey Dee," Mikey popped his head in the dojo. "I'm out of the special ingredient you wanted on the second pizza. But, I called April and she said she and Casey would meet me at the usual manhole to drop it off in a few hours after they're done with patrol. Oh! And Leo, are pancakes an ok breakfast substitute?"

"Um, sure?" I said as Mikey skipped out of the room, humming the _Crognard_ theme. "Can't April and Casey just come to the lair to drop off whatever Mikey needs, though?"

"Well, see, it's uh, uh," my normally eloquent brother fumbled over his response. "I, uh, don't want them to make the trip?"

His voice pitched upwards in an obvious lie. Whatever the reason was, it obviously had something to do with my, _condition_ , and it wasn't good. I gave him a moment to collect and phrase his thoughts, but when his mouth closed and refused to reopen again to rectify his lie, I realized I'd have to take a more direct approach.

I gently cupped his face, and forced his chocolate eyes to meet my ocean blue. I felt something shift behind my eyes, a gentle, not-quite painful pressure. He made no move to pull away, though his eyes widened a bit in, _fear_?

"Donatello," I softly commanded, ignoring the strange look. "Whatever the reason is, I can handle it. I've dealt with much worse news and you know it. Now tell me the truth. Why won't you let April and Casey come to the lair?"

"The lack of blood you have consumed leads to a sixty-seven percent chance of attacking the next non-immediate family member on sight," he answered quietly, flatley, eyes glazing over slightly. "If you consume blood, the chance drops to forty-three percent, as it is still likely that you will see them as intruders to your territory and attempt to dispose of them accordingly. Therefore, until proper measures can be constructed to counteract your abilities, and until I'm sure I know what all of those abilities are, I am banning all visits to the lair in the interest of the safety of our adopted siblings and friends."

I let go of his face and backed away, surprised at the robotic bluntness of his answer. I was expecting a long winded, sugar coated explanation that he would normally give in a situation like this, not a response that was so cold and...

Emotionless.

Categorized me as nothing more than a subject for study.

An animal.

A _monster_.

Raph's eyes froze open wide as he stared between me and Donnie, as though he wasn't quite sure who he should be more horrified with.

"I," Donnie whispers, "I didn't mean to say it like that."

He moved his gaze from me to the ground, and I found myself forcing down my feelings of displacement and loneliness and monster in favor of finding out what was wrong with my brother and how I could make it better. His soft revelation led me to believe that it must have been something I did.

"Raph," Donnie breathes into the quiet.

"Leo's eyes were glowing," he responds to the unasked question. "When Leo grabbed your face, his eyes were glowing and once you met his eyes, you zoned out and, well..."

He trails off, my stomach falls, and a memory flickers across my mind as it clicks.

*)><(*

_Mikey let out another girlish scream, hiding underneath his blanket. Raph's eyes were wide, but he quickly smothered his fright underneath a hard smirk and a comment about the lameness of the movie. Donnie, after the initial moment of terror, started mumbling about the scientific improbabilities of what was happening as he curled tighter into my side. I held him tighter, and it definitely wasn't because I was scared._

_Nope._

_Not at all._

_Fearless big brother, right here._

_Ahem._

_Anyway, Master Splinter had gone to bed long ago, and the third film in our horror movie marathon flickered across the screen. Mikey had decided — despite being told the opposite on several occasions —that nine years old was certainly old enough to stay up late watching old horror films._

_And he had the bright idea that maybe, just maybe, it would be a good idea for his older brothers to join him, though it definitely_ wasn't _because he was scared._

_He "convinced" Raph by calling him a chicken, Donnie by promising to help him clean the lab, and —this is kinda embarrassing —me by pulling out his stupid, irresistible puppy eyes._

_Besides, someone had to keep an eye on my unruly younger brothers._

_We had already watched Frankenstein, some werewolf movie, and were in the middle of our first vampire film of the night._

_There was no way any of us were going to sleep for the rest of the week, and I was willing to bet a month's worth of chores that at least one or all three of my brothers would be in my bed after a nightmare tonight._

_My focus shifted back to the screen, as the vampire rounded the corner, stalking off to find the last of the girls that had helplessly wandered into his castle. He had already killed two, and was off to make the third one his wife. He finally found her, and the girl screamed as she suddenly couldn't move. The camera focused on his glowing eyes. The slight pulsating and a gentle call to come to him saw the girl walking towards him in a daze._

_"That's not how hypnosis works," Donnie said, squinting at the screen._

_"And how would you know, genius?" Raph spat back. "You ain't never been hypnotized in your life."_

_"I don't need to be hypnotized to-"_

_"SHHHH!" Mikey hissed from his spot next to Raph. "I'm trying to watch a movie here!"_

_My two middle brothers settled for glaring at each other, and my attention drifted back to the screen just in time to see the vampire's fangs sink into the poor girl's neck, obviously fake blood spewing everywhere. I wrinkled my beak, slightly disgusted by the gory sight. In contrast Raph cheered quite loudly._

_"NO, NOT THE PRETTY LADY!" Mikey sobbed at the events on screen, rediscovering the dark cover of his blanket._

_It was a wonder half of New York hadn't woken up at our noise. Or Master Splinter._

_"SHHH!" we all hissed at Mikey._

_And —with reactions that dramatic —I become more and more confident I'd find my baby brother at my door tonight, convinced that a vampire would be there to suck his blood because he was the "cute one" or something like that._

_I gave a large, weary sigh._

_At least all I had to do was convince him that vampires weren't real._

*)><(*

I had just hypnotized my brother.

With my eyes.

Some small part of me felt a little smug proving Donnie wrong because, yes, hypnosis can work exactly like it did in the horror film.

However, a much, much louder part was horrified that I had just _hypnotized my brother_ and how _that_ was all kinds of wrong.

I closed my eyes, and turned away from two brothers. It was the only way I could think of to keep them safe.

"I," I whisper softly. "I'm sorry, I'm so, so sorry."

I rushed out of the dojo, but an olive green hand latched onto my wrist before I got very far. I could almost hear the lightbulb go off as my genius brother came to the exact same conclusion I did.

"It's not your fault, Leo," Donnie said. "You are still figuring out this whole vampire thing, and there are bound to be a couple of missteps along the way. In all honesty, most of the experiments Mikey and I designed are to trigger these types of missteps, just in a more controlled environment. If anything, I should be apologizing for thinking of you in such, harsh terms."

"But," I countered, "I wouldn't have ever found out if-"

A comforting hug cuts me off.

"It was an accident Leo."

"But-"

"An accident. I'm fine, and nothing's injured except my pride. A little bit. And I'll get over it."

I keep my mouth closed, allowing myself to just enjoy the warm, gentle hug. I relaxed as I heard the two other heartbeats in the room gradually slow, feeling the last of the tension bleed out of the room.

"Okay, enough of all this mushy stuff," Raph declared from his spot on the sidelines. "Let's get back to torturing Leo 'till his powers pop out."

Donnie and I pulled apart and shot a hard glare in our brothers direction.

"Alright, well, I hate to ask you this," my purple banded brother started, giving a slight cough and rubbing the back of his neck, "but I was wondering if you could, do that again? To Raph? Several times in a row?"

His voice pitched upward again, and both me and Raph shot him horrified looks, screaming at the same time:

"You want me to do WHAT?"

"You want me to subject myself to WHAT?"

"I'll give you the commands to give Raph before we start, so we're all on the same page, sound good?" my genius brother proposed, hands held up in a gesture of surrender. "And I'll make sure to snap you guys out of it if anything goes wrong, promise."

"Fine, whatever," Raph consented. "Let's just get this over with."

I nodded, and Donnie started giving me various commands to transfer to Raph, from not moving to calling Mikey a genius to pulling his weapons on us, the last command causing Raph to visibly tense up. It took me a few minutes to figure out what exactly it was I did when I was trying to hypnotize my brother, but gave a slight internal cheer once Raph reported that he couldn't move.

Mikey waltzed in twenty minutes of hypnosis tests later to let us know that breakfast was ready, but not before he asked Donnie about why Raph and I appeared to be engaged in the world's most intense staring contest.

"Leo discovered he has hypnotic abilities," Donnie answered, not bothering to look up from his notepad.

"So now he can hypnotize me to clean my room?" he whined overdramatically. "My beautiful sweet, three month old pizza collection!"

That would certainly explain the smell emanating from his room.

"No, nothing like that," Donnie explained as Mikey gave a large sigh of relief. "Leo's hypnotic abilities are surprisingly limited. He can only force someone to not move and compel them to tell the truth, as far as we can tell. I have one more test I want to run, and then we'll meet you in the kitchen for breakfast, ok?"

Donnie paused as though a lightbulb just went off in his head.

"But before you head back," my scientist brother asked him mischievously, "did you ever want to find out what really happened to your Gameboy Color?"

Raph sweat-dropped.

"I already told you, Mikey must have lost that old thing in his mess of a room," he said, almost too quickly.

"Oh really?" I grabbed his face, allowing my fangs to accent the evil grin that spread across my face, forcing his eyes to meet mine. "Let's find out the truth, shall we?"

He struggled a moment before visibly relaxing. The answer then spilled robotically from my hot-head brother's mouth.

"I stole it when we were eleven to play a wrestling game I found in the sewers."

"And why did you never give it back?" I pressed.

"'Cause I thought it was funny to watch Mikey turn the house upside down trying to find it. And then I actually lost it in the sewers two weeks later, so I kept up the lie to cover my tracks and avoid getting in trouble."

"I KNEW I DIDN'T LOSE IT IN MY ROOM!" Mikey half-roared, half-screamed as he hurled himself at my still-dazed brother. Raph was suddenly pinned, and non-to-happy about this particular fact. The pin was surprisingly secure, and try as he might, Raph was stuck. Mikey allowed an easy, evil grin to cross his face.

He wriggled his fingers, and began running them up and down Raph's sides as peals of laughter rose from my helplessly trapped younger brother, who was pleading for the orange-banded turtle to stop his relentless tickle torture.

"NEVER RAPH! MY POOR GAMEBOY SHALL BE AVENGED!"

Raph sent me and Donnie a pleading stare, begging us to save him from the little monster.

We ignored him in favor of laughing at his predicament instead.

The smell of something burning wafted in through the dojo doors, pulling my attention from the very amusing scene in front of me.

"Um, Mikey?"

"Not now Leo, I'm busy getting sweet, sweet REVENGE!"

"Are you too busy to deal with the pancakes I can smell burning on the pan?"

"NO! Not my sweet, fluffy flat cakes of deliciousness! NOOOO!"

He got up and bolted from the room, finally giving Raph a chance to catch his breath.

Breath caught, Raph stalked off to join Mikey in the kitchen, an small smile ghosting across his face even as he muttered about annoying little brothers and their stupid tickle torture.

Donnie and I shared a fond, knowing eye-roll and a shake of our heads before following after them.

I vaguely wondered how long this happy peace could last before I shattered.


	7. Chapter 7

**Summary for the Chapter:**

> Leo's power's just don't show up by themselves part two: the power of "it".

**Notes for the Chapter:**

> Hello again!
> 
> I'd like to apologize for the little bit of a wait, but hopefully this is worth it.
> 
> Once again, a huge thank you to anyone who has kudosed/bookmarked/commented this story so far, as it still boggles my mind the people are actually enjoying this honestly kind-of niche story I'm writing.
> 
> Have a disclaimer that I don't own the turtles and Nick does.
> 
> Onto the story!

*LEO POV

Mikey's breakfast was delicious, as always. The pancakes were perfectly light and fluffy, and conversation was pleasant and stayed away from recent events, for which I was grateful.

However, it took me a good chunk of the meal to figure out how to take a bite without cutting up the inside of my mouth with my fangs. I was not exactly keen on reopening the wounds from the last time they drew blood, no matter how _good_ it had tasted. By the time I was on my last pancake, I finally figured out the key was to cut up my food into tiny pieces, and chew very slowly and methodically.

My fangs weren't the only issue with my new biology I was noticing. I should have felt full after eating eight pancakes . Shell, normally I felt full after eating just six. But, even with all that food, I still felt empty.

My eyes wandered to the soft, exposed, succulent flesh of Raph's neck, a soft, gentle thumping of several out-of-sync heartbeats lulling my ears...

I jerked myself out that train of thought, realizing exactly _why_ I still felt like I hadn't eaten anything at all.

Instead, I choose to contemplate what other tests I would have to endure this evening. Donnie had mentioned that I wouldn't even realize most of the tests _were_ tests until something weird happened, so they could be _anything_.

On top of that—apparently—theses experiments were born from a combination of Donnie's scientific knowledge and Mikey's bottomless catalogue of the supernatural from his wide selection of comic books and cheesy B-horror films. Which was definitely _not_ a combination that had me the _least_ bit nervous _at all_.

And—to top it all off—Donnie would be focused solely on the data collection of my new abilities, with _Mikey_ being in charge of running the actual tests themselves.

Safe to say, my abilities were _not_ the only thing that would be tested over the course of the evening.

With breakfast officially over, Donnie excused himself, heading to his lab, while Mikey grabbed my wrist and dragged me out to the abandoned subway tunnel in front of the lair, leaving Raph to take care of the dishes. Upon reaching the entrance, he began to lightly stretch, and instructed me to follow suit. Five minutes later Donnie joined us, sitting down just outside the turnstile entrance, notebook and pencil in hand.

"Alright bro," Mikey asked, in a faux serious voice, finishing his stretching. "are you sure you're ready for this?"

I gave an eye-roll, only a _little_ nervous about whatever was about to happen, but nodded nonetheless.

"Are you sure?"

"Yes Mikey, I'm sure."

His serious face fell and an easy smirk formed in its place.

"YOUR IT!" he yelled, slapping me on the arm and taking off. "NORMAL BOUNDARIES BRO!"

I froze, staring after his rapidly-retreating shell.

Did, did my brother just _tag_ me?

In hindsight, it really shouldn't have surprised me as much as it did, especially considering some of the pranks my little brother loved to pull.

"Are you going to chase after him or just stare off into the distance all day?"

And this definitely wasn't a prank, based on Donnie's words. This was another test.

But testing _what_?

I shook off the question and tore after my baby brother.

Then promptly realized _why_ he held the title of the fastest in the family.

Mikey was a good ways ahead of me yet, and _still_ putting distance between us. I had no possible hope of catching him at the speed I was running at. The only way I had even a chance at tagging him was if I played this out strategically, and outlasted Mikey's full out sprint by maintaining a steady jog.

My brother turned around and stuck his tongue out at me before facing forward again and somehow running even _faster_ than before. A flash of annoyance ran through me at the childish taunt, and I disregarded my plan to pace myself in favor of pumping my legs even harder to catch the orange-banded speedster.

The world blurred for a moment. I saw a green and orange blur flash by. Wind slammed against the front of my body. It took me a full minute to force myself to a screeching halt at the end of the tunnel.

What.

Was _that?_

Annoyed determination transitioned into baffled confusion as I stared at the rotting boards of the blocked off tunnel that made up the far boudry of our playing field. From experience, I knew that should have taken me at least another fifteen minutes to reach this point. Instead, I had traversed the distance in the span of one minute.

I stood, staring at the wooden wall, trying to process whatever the _shell_ just happened.

Mikey finally came into view about eight minutes later, and his heavy breathing shook me out of my thoughts. I jogged down the tunnel, cutting the distance he had to travel to reach me in half.

"Dude, you just, shot past me," Mikey said in between breaths.

"Yeah, I guess I did."

"How'd you even do that?"

"I have absolutely no idea. I was behind you, the world blurred and a minute later I'm at the end of the tunnel."

My brother's face scrunched up in thought. He gave a long, loud hmmm, which was cut off as a light-bulb went off above his head.

"You've got super-speed bro!" he declared, a bright smile lighting up his face. "Common' Leo, Donnie _has_ to know about this!"

He moved to grab my wrist, but I jerked my hand back, and an idea forming in my head. This new piece of information—for once—was something actually kind-of cool. Ok, scratch that, it was really, _really_ cool. Seven-year old me was gawking at just how awesome it was, and seventeen year old me was hard-pressed to keep from grinning from ear-slit to ear-slit at being able to finally experience my favorite super power.

And, as they say, with great power comes the great responsibility of using it to aggravate your brothers.

Mikey's look of confusion quickly morphed into a look of fake annoyance as I smirked and slapped him on the arm.

"YOU'RE IT, MIKEY!" I yelled over my shoulder as I sprinted away, allowing my super speed to carry me far away from my brother, but not quite far enough so as to hear the "NO FAIR!" he yelled back.

I practically flew by a green and purple blur, laughing and letting out a whoop as I pushed myself to go even faster. However, I was so focused on enjoying the exhilarating _rush_ that I failed to notice how the tunnel curved sharply to the right until it was too late to slow down.

Not too keen on slamming into the wall, I jumped instead, positioning my feet so I could kick off the wall and perform a back-flip to lose the extra momentum. Instead of gracefully kicking off the wall, however, my feet found purchase and _stuck_ , so I was forced to keep pumping them as I ran up the curved wall. Finally, I was able to slow myself down, except I was now faced with another dilemma.

I was now standing on the ceiling.

Upside down.

And the only way to get down was the same way I came up.

I spent the next several minutes having an intense debate with myself as to whether or not I should risk taking another step, as there was a very high chance that doing so would cause me to crash to the ground, which would surely cause me to injure myself.

Which is the outcome I was trying to avoid in the first place.

"Leo, since when did you become Arachniboy?" Mikey exclaimed in awe as he rounded the corner. Startled, I registered the tingling sensation on the soles of my feet the moment it stopped. Gravity kicked back in and I fell onto my carapace between the rusting rails of the abandoned subway track.

"Since about ten minutes ago," I groaned as I rubbed my sore shell.

"That was the coolest thing I've seen in the past fifteen minutes bro! Do you think you could do it again?"

I shrugged, since I wasn't entirely sure exactly _how_ I ended up on the ceiling.

Mikey looked slightly disappointed, but the look faded as quickly as it came. He gave a goofy grin, slapping me on the carapace before sprinting away again.

I rolled my eyes, and set off at a much slower pace so I didn't face a repeat of the incident.

The title of "it" was traded back and forth as we made our way back to the lair's entrance, teasing and giggling at each other the whole time. Mikey had run on ahead—despite currently being "it"—to see if Raph was done with the dishes, and the distinct smell of smog and sweat paired with the scent of motor oil from Donnie confirmed that he was.

I heard Mikey yell "YOU'RE IT!" as I rounded the corner. I was greeted by the sight of my hothead brother chasing him with an annoyed scowl on his face. The scowl quickly morphed into a grin, however, as Raph changed directions and headed instead for his immediate younger brother.

He slapped Donnie on the arm, jolting the genius from his musings as he sprinted away yelling about how the purple-banded turtle was "it". Donnie, for his part, took a split second before getting up and chasing the red-banded turtle with equal vigor.

With all four of us now in the game, it wasn't long before the simple game of regular tag morphed into ninja tag then devolved into catch the vampire-turtle, who—after a minimal amount of gawking and complaints about how it was "cheating"—definitely hadn't begun abusing their newly found super speed to evade the title of "it".

Ahem.

This time, though, I was much more aware of all the curves and bends in the tunnel, even managing to replicate the stunt I pulled earlier—at Mikey's insistence—and confuse the shell out of Raph and Donnie for what must have been the umpteenth time that night, both their mouths dropped open wide and their eyes comically large. I laughed hard enough to detach from the ceiling again, causing all of my brothers to double over as I crashed onto the ground. All of them quickly reigned in their laughter just long enough to take advantage of my vulnerable position to pile up on top of me and keep me pinned on the ground. Raph wiggled his fingers, and soon a tickle war broke out, every turtle for himself, our loud laughter echoing off the subway walls.

Leave it to Mikey to come up with a test that not only triggered two new abilities, but cut through the heaviness that had permeated the lair ever since the incident.

The loud ringtone of a T-Phone interrupted our laughter, but it wasn't enough to wipe off the wide smiles that now rested comfortable on all of our faces.

"Hello?" Mikey pulled the phone away as someone yelled loudly on the other end.

"Three hours already?! I'm sooo sorry April I totally lost track of time and I left my-"

"I can be there in twenty minutes, thirty tops. I'm so sorry Ap-"

"Hanging up now."

Mikey—with a slight look of terror on his face—quickly hung up the phone and shot off to meet up with our human friends, not even bothering to give us a goodbye.

We had all been on the wrong side of April's anger at one point, and the angry red-head was someone not even _Raph_ would dream of crossing.

A shudder ran through us in sympathy for the likely torturous talking to Mikey was about to receive at the hands of our honorary sister.

But, now that our baby brother was gone, my genius brother could unleash his scientific curiosity all over my two abilities. He turned to me, an almost manic look in his eyes and a borderline too large grin on his face.

I shot a helpless, pleading look at Raph to pull me away from my now mad-scientist brother. He crossed his arms and tried and failed to smother his laughter.

Clearly, he was out for revenge after abandoning him to Mikey's tickle torture.

I shot him a death glare as Donnie grabbed my foot and pushed it against the wall.

This was going to continue to be a long night.


	8. Chapter 8

**Summary for the Chapter:**

> Leo's powers just don't show up by themselves part three: Pie and organic barbells.

**Notes for the Chapter:**

> Greetings and salutations!
> 
> It's been wild two weeks, lets just say that. Thank you all for being so patient with me as I work out how to balance the craziness that is my life.
> 
> Speaking of thanks yous, I'd like to give a very big one to everyone who has left a kudos, bookmarked, and commented on this story so far! It really does mean the world to me and always leaves me with the biggest, stupidest grin on my face whenever I see that people are enjoying this.
> 
> Today's Japanese is brought to you by: Google Translate, the world's most unreliable translator! So, if anyone notices any mistakes, please don't hesitate to let me know! Translations can be found at the end of the chapter.
> 
> This story is also brought to you by: Nickelodeon, the proud owners of the TMNT.
> 
> With all that out of the way, onto the story!

*LEO POV

The next hour of expiration was a constant stream of Donnie saying "do this" or "try this" or "just one more test, for the sake of science!" while I walked on the ceiling and ran up and down the tunnel a million times. Raph —the lucky hot-head—left to go watch TV after making fun of me falling off the ceiling for ten minutes. My monotonous testing torture to come to a blessed end when Mikey got back from meeting with April and Casey, arms laden with gifts from our human friends.

Apparently, he had conned April and Casey into getting more than just one ingredient.

Which was fine, because we had to get groceries soon anyway.

"A little help?" the orange-clad turtle asked, several of the plastic bags on his arms dangerously close to breaking with how full of supplies they were.

Donnie and I rushed over, and Mikey gave us several bags each. However, he was oddly particular about who took which bags, so I'm guessing that there were items he asked for that he didn't want me to see.

I glanced into the bags I was given, and was mildly surprised to find a small selection of medical supplies. Mikey must have noticed how low the supplies were getting in our first aid kit.

Donnie would certainly appreciate the items.

Ever since my scientist brother had been forced to take up the position of team medic—when we started arriving home with injuries too severe for Sensei to deal with —he had prided himself on making sure he had enough supplies and knowledge to basically run his own mini-hospital. After our first encounter with the Shredder, he went on a run to a junkyard that was close to where a small clinic had recently shut down to procure the items he needed to convert a little used corner of his lav into our current medbay. He scrounged up enough parts to fix up a heart monitor, a small x-ray machine, and two cots, which he modified to allow for our curved shells. He even managed to find a mini fridge, which he used to store temperature-sensitive samples, medicines, and our small blood bank.

Anything that we couldn't scavenge —needles, IV bags, drugs, blood-bags, gauze, bandages, anything that needed to remain sterile or was one time use —he either ordered online and had shipped to the O'Neil residence or we, _pre-paid_ restitution on and stole from several of the smaller pharmacies nearby, often using money we, _reclaimed_ from the Purple Dragons or the Foot.

I took my bags to the med-bay, dropping them on the nearest cot for Donnie to sort through later, while my other two brothers took their bags to the kitchen. Both were animatedly discussing _something_ , but I couldn't quite make out the words. I was just glad those two seemed to be entertained by something that wasn't me.

Finding myself with a distinct lack of anything to do at the moment-and the TV otherwise occupied, if the whisper-screaming was anything to go by-I elected to take the time alone to meditate in the dojo. Upon entering, I grabbed a match and relit a few candles for ambiance. I settled myself into a lotus position, closed my eyes, and took a deep breath in.

Only to be assaulted by the one too many scents swirling through the lair.

I switched to taking shallow breaths, focusing on identifying one scent at a time, much like I did when I first woke up. My siblings scents, the sewer, and whatever nauseating concoction Mikey was making in the kitchen all drifted in and out of my attention, and I fell into a light, meditative trance.

My baby brother's call for lunch jolted me back to awareness. I blew out the candles and proceeded to make my way to the kitchen.

I immediately gagged when I entered the room, as a horrible smell slammed into my nostrils. I narrowed down the source of the scent to one of the two pizzas set on the table. The first looked relatively normal, and was topped with cheese, pepperoni, jellybeans, and pineapple, and the second one, well...

The second one was covered with a red and brown homogeneous blob that I was not entirely sure wasn't sewer sludge. Chucks poked out the mixture, adding to the appearance which made me want to gag almost as much as the smell did.

A wave of exhaustion slammed into me from nowhere, and every single one of my muscles transformed into lead. The smell became stronger, and I realized that at some point I had started fighting the strong urge to get myself as far _away_ from the source of the scent as I could.

I brushed the sudden lethargy aside, as it was probably just a byproduct from all the tests I had participated in today pretty much nonstop. Certainly nothing either me or my brothers needed to worry about. I grabbed a piece of the relatively normal-looking pizza, assuming the sewer sludge pizza was likely the source of the smell.

But when the smell got _worse_ as I brought the piece closer to my mouth, I realized I had assumed wrong. Perhaps Mikey did something weird to _both_ pizzas? It certainly wouldn't be the first time.

Regardless, the normal-looking pizza still appeared to be the more palatable of the two options.

I forced the bile that was rising back down my throat, and took a bite.

And immediately spit it back out.

Adrenaline coursed through my veins and the exhaustion that I was feeling vanished. I needed to get _away_ from whatever that awful smell and the _taste_ was somehow even _worse_ and it made me feel weak and woozy and I had to be strong and I needed to _get away I needed to get away get away GET AWAY-_

" _Kokyū, Leo_ ," Mikey's calm talking brought me out of my rapidly spiraling thoughts. " _Tada iki o shite. Anata wa anzendesu. Kokyū suru._ "

The fog, lethargy, and panic that laced through my body and mind faded as I matched my breathing to his.

I was in the main lair space. Though _how_ I ended up in the main lair space was a mystery. Mikey was gently rubbing my arm while Donnie and Raph stared at us concerned. And all three of my brothers looked, _guilty_?

" _Daijōbu, Leo?_ " Donnie asked as he slowly approached me to look for himself. " _Dō shita?_ "

" _Hai_ ," I answered, pleased to find that it wasn't _entirely_ a lie. "And I have absolutely no idea. We can figure it out after lunch though, I still feel like I could eat half the pizza in New York."

Donnie raised an eye-ridge—not entirely convinced at my answer—and joined my brothers as they headed back to the kitchen. I took a moment to steal my nerves and followed behind them, much more prepared for the awful smell this time.

"Mikey, what _exactly_ did you put on these pizzas?" I asked, eying the two pies warily, not wanting to take another bite of either pizza until I knew what was on it. The strange exhaustion that had left when I was in the main room returned with vengeance as I sunk into a stool.

"Nothing besides the usual, bro," he assured me. I raised an eye-ridge in question, but he just blinked innocently. "Well, at least on my famous jelly-bean supreme. I can't help that you can't deal with the garlic, bro. Which is why I made you this special, garlic-free, vampire-friendly pizza, that features a barely flame-kissed steak drizzled in blood sauce! Don't worry though, I just used the extra blood from the steak, so no worries about the mortality of it or anything!"

He flashed me a wide smile, obviously very proud of himself.

Donnie mumbled something that resembled that the word was "morality", not "mortality".

My brain came to a complete halt as I processed his words, staring down at the source of my malady.

The stupid peice of pizza.

That had _garlic_ in it.

 _Vampires_ were weak to _garlic_.

 _I_ was now a _vampire._

I felt like a complete and total _idiot_.

No wonder it tasted so bad.

Or why I felt like complete and total _crap_.

Mikey snatched the slice on my plate as I stared at it, once again swallowing back both bile and the urge bolt out the nearest exit.

"Nice going, shell brain," Raph said around his slice of pizza. "I think you broke him."

"I thought he already knew, bro," my baby brother said, faintly confused, which morphed into concern as he stared at me. "You doin' okay, Leo?"

As a matter of fact, no, no I was not.

" _Hai_ ," I responded instead, not wanting to cause additional worry. To prove that I was, in fact, okay, I grabbed a slice of the other pizza and shoved it into my mouth. Had I not been fighting the urge to throw-up, I would have thoroughly enjoyed the way the coppery taste danced on my tongue, twirling between notes of earthy onion and sharp tang of the cheese.

I managed to finish a whole slice without throwing up before making my excuses to exit the room, heading for the couch to wait for the last bits of unnatural exhaustion to wear off. The gentle sounds of my brothers squabbling over who would do the dishes drifted in and guided me into a light doze, which I woke from when Mikey dramatically flopped down in the seat next to me.

He flicked on the TV to some documentary about Central America, then promptly proceeded to start complaining over the program about how he got stuck on dish detail when Donnie pulled Raph to set up the next experiment in the dojo. While he kept his complaining to a loud whisper —as he was right next to my ear-slit—he more than made up for his normal volume level in large, wild gestures that I had to duck under and around more than once.

At some point, he changed from complaining to a very, _interesting_ retelling of the plot of the latest Crognard episode, complete with character voices and some details that I'm fairly certain were not included in the actual episode.

I allowed the documentary to become background noise, becoming immersed in the story my brother was weaving. So long as one didn't need an accurate version of the event, my brother was actually quite the gifted storyteller.

Safe to say, when Raph told us they were ready just as Mikey was wrapping up his tale, it was very, _very_ difficult to pull myself off the couch to follow him into the dojo.

My red-clad brother was practically buzzing with excitement, and I resisted the urge to facepalm as I entered the dojo and saw why.

Raph's weight bench, plus every single weight he owned—plus a few I wasn't aware he did—was sitting on the center of the dojo floor.

"Alright Leo," Raph said. "Whoever can bench more weight does the loser's chores for a week."

No _wonder_ he was so excited.

A competition.

That he had won every single time except _once_.

And that was only because he was recovering from an injury.

That I was _not_ going to be able to avoid like I usually did.

"This is another test, isn't it?" I heaved a large sigh as all three of my brothers gave guilty smiles.

"At least this one doesn't involve poking and prodding," Donnie said, voice pitching upward.

"Yes, but it will _lead_ to poking and prodding."

Donnie's smile became tight as he let out a nervous laugh. He needn't have worried, however, as I already knew I was going to agree to thier stupid contest.

Doesn't mean I couldn't use their desperation for my own benefit.

At my hesitation, Mikey took it upon himself —as part of his sworn duties as a baby brother—to give me his absolute biggest puppy eyes he could muster.

I had lived with him too long to fall for that trick.

Then Raph and Donnie decided to join him.

Tough-guy _Raphael_ and methodical scientist _Donatello_.

The combined power of their puppy eyes was too much for me to keep up the façade any longer.

" _Fine_. I accept, on the condition that Raph goes first _and_ that I get a week off of chores regardless of the outcome of the competition."

No good, rotten, adorable little brothers.

Who I managed to manipulate into giving me a week to catch up on my fifth _Space Heroes_ series rewatch.

After some brief instructions from Donnie that boiled down to "don't be dumb", Raph laid down on the bench, ready to start his set. At my purple-clad brother's request, Mikey took up the spotter position. The bar was placed on the hooks and reasonable twenty-pound weights were added to either end. After every press, our baby brother added another set of weights onto the ends of the bar.

Twenty minutes and four-hundred thirty pounds later, Raph—covered in sweat and panting—was forced to quit. He shot me a confident, "beat that" smirk—not only because he just beat my personal record of four-ten—but because he'd just beaten his own record of four-twenty as well. I myself to two months of dishes and laid on my carapace, gripping the bar between my hands, ready to press.

Thirty minutes and I honestly have no idea how many pounds but-it's-definitely-more-than-Raph-later, each press was only minimally harder than the first. My hot-head brother had gone from upset scowling to thoroughly impressed gawking too loud cheering with every press and weight added. Just as I was starting to actually feel a little bit of resistance, we'd run into a problem.

Every weight we owned was currently on the bar.

And I could _still_ take more.

Even though I had completely blown Raph's record out of the water by about a hundred pounds, we were all still curious as to exactly _how much_ weight I could take.

"Dudes, I just had a genius idea!" Mikey suddenly declared, his tone screaming that—whatever it was—it would be a bad idea. "I could climb onto the bar and become a weight. OOH! And Raph could be the other weight! Y'know, so it balances and stuff."

"Mikey, I don't think that's a good-"

"Mikey, my main turtle, that's the best idea you've had all day!" Raph cut Donnie off, a large grin threatening to split his face in two.

Somewhere in the back of my mind, a little voice was screaming that yes, this was a _very_ bad idea.

I ignored it, my curiosity as to how much I could lift winning out over my common sense.

Donnie threw up his hands and gave a loud sigh as I gestured for my brother's to get ready to hop on the bar.

"You know what? Fine! Whatever, but don't come whining to me when you're all banged up and bruised from a nasty fall or if your arm breaks because you decided to be dumb and become organic barbells."

"But dude, if we're the weights, and Leo's lifting, then who's going to be the spotter?" Mikey asked as all eyes turned towards Donnie. Despite just saying how he wanted to limit his involvement in our great idea, he trudged over to take the position, realizing that he would have to be the one, sane responsible person in a room full of idiots. Raph and Mikey then climbed onto opposite ends of the pole, sat on top of the weights already there, and gave me a thumbs up.

We were ready to perform the most spectacular stunt known to mutant-kind.

With the large bend now visible in the steel pole, I briefly spared a thought of wonderment as to how it hadn't snapped in half yet.

I took a deep breath, curled my hands around the bar, and slowly began the press. My arms were shaking, not from the weight—though I could definitely feel that now too—but from the effort of keeping the bar balanced so my brothers don't fall off. The only sound in the room was my heavy, measured breathing as I worked my way through the press.

I gently brought the bar back down, and all of my brothers—even Donnie —started to cheer at the feat.

But I still had room on the bar to fit one more turtle.

"Donnie?" I invited. "There's still space on the center bar if you want in on the action."

He eyed the situation warily, clearly waging a war between his teenage hormones and his logical, fun-killing conscience.

"Y'know, if Casey were here, he would've gotten on the center of the bar no questions asked. Which I think April would find pretty impressive, don't you?"

Raph's jab made the decision for my purple-clad brother, and Donnie scrambled to sit in the middle of the bar, his butt right above my face.

It certainly wasn't the most pleasant image I've ever looked at.

I repositioned my hands and began the next press. A small grunt of effort slipped out as I forced my arms skyward before bringing them back towards the ground, being mindful to keep the bar as balanced as possible.

As soon as I set the bar down, a huge, dumb grin planted itself on my face as loud cheers erupted from my younger brothers, causing me to wince. In turn, my brother's brought their celebrating down to a much more reasonable volume level. Raph slapped my carapace as I sat up. Mikey went straight for glomping me with a hug, a huge smile on his face as he rambled about how cool and awesome both the feat and I were. I caught a congratulations in the sting of scientific mumbo-jumbo that excitedly spilled from Donnie's mouth that was _probably_ about the amazing feat I had just completed.

The small victory filled me with warmth, and I started to think that maybe this situation would turn out okay after all.

**Notes for the Chapter:**

> Kokyū, Leo- Breathe Leo.
> 
> Tada iki o shite. Anata wa anzendesu. Kokyū suru.- Just breathe. You're safe. Breathe
> 
> Daijōbu, Leo?- Leo, are you alright?
> 
> Dō shita?- What happened?
> 
> Hai- Yes


	9. Chapter 9

**Summary for the Chapter:**

> Experiments are over. For now.

**Notes for the Chapter:**

> Hello and welcome!
> 
> It's been a while, and I'd like to thank all of you for patience.
> 
> Another set of thank yous I'd like to give is for anyone who's kudosed/bookmarked/commented on this story so far, as seeing the notifications and the nice words makes me feel all warm and fuzzy inside every time I look at them!
> 
> Once again, Google translate has stopped by to drop off some Japanese translations at the bottom of the chapter, so if any of them are wrong don't hesitate to let me know.
> 
> And I still can't claim ownership of TMNT, that belongs to Nickelodeon.
> 
> Without further ado, I present to you the story!

*LEO POV

Once congratulations were finished, Donnie had decided that he had enough data to keep him busy for the rest of the night, and headed to his lab to analyze it.

Thus I was finally, blessedly released from the bonds of experimentation.

I breathed a huge sigh of relief, happy to do literally _anything_ else for a little while.

Mikey suggested a _Crognard_ marathon, and, well, I _guess_ that qualified.

However, Raph—begrudgingly—suggested we watch a certain, quote, "lame" space show instead.

Just because it was easier to make fun of than _Crognard_.

Yup.

I'm sure there was no other reason.

The big softie.

Thank goodness.

With Mikey outvoted two to one, the three of us headed towards the pit. I pulled a blanket off the bench, put the VHS in the player, and I took my customary only a few short feet away from the TV, though I had to scoot back until my carapace hit the couch due to my headache flaring up from the brightness of the screen. The theme song started playing and I immediately started humming along.

Raph started to softly sing some dumb parody version of the song to Mikey that insulted the greatness that was _Space Heroes_ , causing our little brother to burst into a giggle fit.

I take it back.

Apparently he _did_ just want to sit and make fun of the show the whole time.

I shot a half-hearted death glare over my shoulder before returning my attention back to the show. Which caused both of them to just laugh even harder.

I gave a wince at their volume, and both turtles brought their steady jabs-turned-running-commentary about all supposedly dumb stunts threw fearless crew of the _Dauntless_ pulled to a dull roar that was _much_ easier on my hearing.

Their insults, on the other hand, I endured with my usual dignity and grace, which resulted in loud shushing and several pillows to both of my brother's faces, much to their amusement.

Eventually, their jabs slowed and then stopped entirely, both turtles succumbing to the call of sleep.

Without my brothers' stream of chatter, my thoughts were free to wander to less than pleasant topics. I felt restless, and needed to do _something_ that wasn't sitting here in the almost quiet.

The dojo seemed like a good place to expel some of my nervous energy.

I shut the TV off, picked up a blanket on the floor and tucked it around my two sleeping brothers. They shifted slightly at the contact, but otherwise remained peacefully asleep.

" _Yoku nemuru, otōto_ ," I whispered as I left the pit.

I paused briefly outside the metal door to Donnie's lab, but ultimately decided to leave him to whatever mad science he was conducting behind the closed doors.

Besides, I know he had slept at some point in the last twenty-four hours at least, so he wasn't in danger of falling face-first into any dangerous chemicals at the moment.

I entered the dojo, electing not to light any candles, as the ambient lighting of the surface world and the silver light of the moon were more than enough for me to see by.

I began with some light stretching to get rid of the stiffness from staying in one position on the floor for so long. Once I felt sufficiently warmed up, I grabbed a pair of _bokken_ from the weapon's rack and began running through the simplest katas and working my way up towards the most advanced. I flowed from one form to the next, losing myself in the movements of a deadly dance, tearing through hoards of invisible enemies. A thin layer of sweat had built up over my body as I finished the set and bowed to the empty room. I placed the _bokken_ back in the weapons rack. It was a good workout, and I felt calm enough to try to meditate under the sprawling branches of the oak tree.

I settled myself into a lotus position, taking a deep, measured breath in, followed by another, then another, and soon enough I found myself deep into a meditative trance.

"Hey Leo?"

A loud, angry hiss thrummed through the dojo.

I was at the door before I'd even registered that I'd moved.

"LEO! LEO IT'S JUST ME! IT'S JUST DONNIE!"

The hiss cut off as I snapped my open jaw shut. I felt something in my eyeball shift as I blinked to clear the haze that had filled my mind.

The rapid heartbeat failed to slow down as much as it should. There was a smell that I couldn't quite identify, subtle and unpleasant.

That was fear, a little voice in the back of my head supplied.

What.

How, how the shell did I _know_ that?

My brother stared at me, holding his med-box up as a shield to protect him from…

From _me._

"Donnie?" I asked, knocking off the last of the haze and forcing my feelings about the situation into a little box to deal with later. "I'm sorry, I'm so, so sorry, I didn't mean to-"

"It's okay, Leo," Donnie gently cut me off. "It's fine. I'm fine. I'm not hurt, it was an accident, I didn't mean to startle you."

His still raised heartbeat and the lingering fear smell contradicted the fact that he was "fine", but I let it slide—for now—still too keyed up myself.

I took a deep breath in, and let out, finally calmed down.

"Any idea why I lost it?" I asked him.

"Well," he started, lowering the med-box. I gave a groan, knowing full well where this was going.

"The short version please."

"Based on several physical factors: barred fangs, slitted eyes, and tensed muscles, you entered the, _fight_ fear response when I startled you."

"I didn't hurt you, did I?" I frantically began to scan my brother for any new injuries.

He rolled his eyes at my frantic worrying, mumbling about my resemblance to a mother hen.

"You just hissed at me and did your best scary face. I already told you I'm completely fine, Leo."

Clearly I had done a good job of "being scary", because—though his heartbeat had slowed down enough—the fear scent had yet to disappear.

"So, um, is there a reason why you're not asleep yet?" Donnie asked. "I saw Raph and Mikey conked out on the couch, and with all that happened today, I thought you would have joined them in dreamland."

"I was feeling restless," I shrugged. "Though, all things considered, I don't think you're one to talk, mister king-of-the-four-am-in-the-name-of-science."

"Today it's mister king-of-the-seven-am-in-the-name-of-science to you," he threw back.

"Wait, it's already seven in the morning?"

"Yeah, the sun'll be shining through the grate in a few minutes," he confirmed. I wondered where in the heck the past five hours had wandered off to.

"So, um," I switched topics, "what did you need from me?"

"A, uh, a _blood sample_?" he said voice pitching upwards, and my eyes flew open wide.

"A _what_?"

"A blood sample. Don't worry though, I think I've figured out a way to keep you from smelling the blood."

He crouched down, opening up the med-box, pulling out rubbing alcohol, a syringe, a cotton ball, and a small jar full of a white, unidentifiable paste. He opened up the jar and I recoiled back as the scent of garlic slammed into me.

"It'll only be open for a minute, I promise," Donnie murmured as he grabbed my arm, cleaning the injection site, and I closed my eyes right before I felt the needle pierce my skin. I forced myself to focus on the scent of garlic, and _not_ on the fact that _blood_ was coming out of my arm and I could _smell_ it right on the edge of my awareness-

And the blood scent almost completely vanished under the unpleasant garlic smell as the paste was placed over the injection site, and a band-aid placed on top of that.

"All done," he said, and I opened my eyes to see a small, _Space Heroes_ bandage on my bicep. I gave my brother a smile, and he responded with a thumbs up as he put away the now filled syringe with the other medical supplies. The garlic smell faded, but didn't disappear entirely, as Donnie closed the container.

"I put a small amount of garlic paste over the puncture site, which should help to cover up the blood smell."

"I'm happy to report that it's working," I said, and my genius brother gave a small, proud smile. "Good thinking Donnie."

A slightly awkward but not wholly unpleasant silence settled over the two of us.

"So," I asked, "what did you need the sample for anyway?"

He tensed at the question, smile vanishing, eyes looking anywhere but at me.

"I, well, I have a theory, and I, well," the normally eloquent genius stuttered. "I ran a test on some blood I drew earlier while you were, _out_ , and, I, the results aren't exactly, favorable for the ideal outcome of my hypothesis. So I want to run the test again, just to, double check."

"Well, what's the theory? What did you find out?"

"I, well, I can't be certain about anything, because there are so many different iterations both in historical legends and in modern media, though the modern media is more Mikey's department, and each of _those_ can be further sorted into at least four to eight different types, and I have no idea which one you fall into because most of your abilities and new ticks fall into several of the categories so I have no idea exactly what you're capable of but I've begun to notice a few habits that really concern me because some of the stuff I read about I really, _really_ hope doesn't affect you or doesn't happen because I only have one viable theory based of the results I've seen and I really, really, don't want it to be true even though all the evidence is _screaming_ that it is because that would mean you came _back_ except you didn't even though you're here and I don't-"

"Donnie, _iki o shite_."

He closed his eyes, taking a deep breath in, letting it out through his mouth. But when he opened them, the shaking got _worse_ , and he stared at me with shimmering eyes as though I were a ghost. His hand flew to his mouth as he fought to regain his normally calm composure when it came to sharing, less-than-positive news. Whatever he had found out, it had shaken him to his core.

I gently wrapped my arms around his shaking form, and any control my genius little brother had on his emotions left as a sob wracked through his body. I was surprised at the ferocity that he returned the hug with, as though he was scared I was going to leave him and never come back. I held him close, whispering a gentle mantra of " _W_ _atashi wa koko ni imasu_ " over and over again, as Donnie allowed all the pent-up emotions for the past few days to run their course.

Eventually, his tears stopped, and his sobs quieted into gentle sniffling, though he made no move to let go anytime soon.

And I intended to let him hold on for as long as he needed to assure himself that I was _here_ and that I wouldn't be leaving anytime soon.

Nature had other plans.

A sudden burning pain seared across my skin. Every inch of me felt like it was on fire and I needed to get away from it but _something was holding me back_ so I threw the thing off and as far away from myself as I could. I let out a loud screeching _hiss_ the same time as a loud _THUD_ and a sickening _POP_ brought me back to my senses. Thankfully, I had left whatever it was that was causing me to burn alive.

I started to panic as my eyes landed on Donnie slumped against the opposite wall, unconscious, his arm definitely not attached to the rest of its body like it should.

"Donnie? DONNIE!" I raced toward my brother, careful to avoid the spot under the grate where we were standing, and where the first rays of the morning sun were-

It was the sun.

The _sun_.

I must have thrown him against the wall in my desperation to get away from the _sun_.

I knew, _knew_ that Donnie wouldn't have blamed me, he would have said it was just another misstep in the process of figuring out, _this_.

Me.

That didn't stop a little voice in the back of my head from telling me that, somehow, this is my fault. That I should have _known_ that the sun was so close to rising and that I should have pulled away front the hug _sooner_ especially after that whole emotional fiasco and-

I didn't have time to play what if. I had more important things to focus on right now.

I crouched down next to my brother, gently prodding his left shoulder, wincing when I found out his arm was dislocated. His breathing was far too shallow for my liking.

"Keep it down Fearless, some of us are tryin' to-"

Raph cut off his sleepy complaint as soon he saw the situation and immediately placed himself on the other side of our purple-clad brother.

I heard Mikey shuffle in a moment later, before he slapped a hand over his mouth to stifle a gasp. He rushed over, but paused a few paces away from the action to give us space to work.

"Leo, what happened?" Raph asked, eyes worriedly scanning over our younger brother.

"Donnie had a, moment, and we were under the grate when the sun came out and, I, I think I threw him into the wall and I'm so sorry and-"

I felt a hand start rubbing circles into my carapace.

"It was an accident, Leo" Mikey said. "Donnie won't blame you, and neither will we. Please don't beat yourself up about it _aniki_."

It was a little late for that.

I shoved my emotions into a small box to be dealt with later for what must have been the millionth time tonight.

Right now, I had a brother who's arm needed relocating.

"Raph, help me hold him down," I said as calmly as I could "I need to relocate his arm and I don't want to risk him injuring himself further."

He gave a small nod and moved into position.

I took a deep breath to steady myself, and immediately the smell of copper assaulted my nostrils. My eyes zeroed in on the source, a currently unaware Donnie.

I reached around to the back of his head, and felt a sticky liquid start to drip onto my fingers from a small cut. I retracted my hand, it came back dotted in red.

I stared at my hand, and then back to Donnie. My eyes traveled to his exposed neck.

And stayed there.

Bile rose in the back of my throat as I realized what was happening. Against my will, I felt my mouth open, my fangs extended. I scrambled as far away from Donnie as I dared, still wanting to be close enough to…

To...

This was my brother, my _brother_ , I can't-I didn't even know _why_ I was _considering_ this, I can't-

"Leo, what, what are you doing?" Raph said. His breathing picked up the same moment I started to smell three distinct fear scents.

I tried to talk, but all that came out was a scraggly hiss, a warning to stay back, just stay back stay _away_ -

"Raph, get Donnie into the sunlight," Mikey's voice cut through my thoughts, his calm, commanding tone reminiscent of the first time we were in Dimension X. "Leo, I want you to head straight to your room and shut the door. I'll meet you there in a sec, I just have to grab something first. Do you think you can do that bro?"

I gave a small, shaky nod.

Raph dragged my pre-my brother underneath the grate, both of us too in shock to protest my baby brother's orders.

I gave one loud hiss before sprinting as fast as I could out of the dojo and towards my room. As soon as I crossed the threshold, I slammed the door shut and started pacing, trying my best to ignore the red that still coated my hands, and the _extremely_ tempting copper smell that seeped in under the door.

I forced myself to focus on other smells. The faint garlic smell from under the bandage. Sewer stench that I was normally nose-blind to. The faint, lingering scent of pizza from earlier. Blood, Mikey's scent as he made his way to my room, blood, the small bit of incense I kept in the top drawer of my dresser _blood_ -

I quickly realized I was getting nowhere. If anything I was making it _worse_. I shuddered, doubling my efforts to fight against the instinct to _go find the injured one and drink_ -

The soft click of my door opening caused me to jump back and hiss at the intruder. My aggression melted into fear at the sight of my baby brother holding a bag filled with red liquid, the name Raph spelled out in bold, black capital letters on the bag.

"Mikey, why did you-"

"If you don't drink _something_ now," Mikey calmly cut me off, "it's only going to get harder to control the urge around live beings 'till you just, lose control and, well, let's just say Jeffery had some serious regrets in _Vampire Hunter_ issue four."

"But, what if I start on this and it grows out of control and I want more and I hurt-"

"We'll cross that bridge when we get there, but for now you've gotta sate yourself bro, or you will actually go crazy. Look, I'll even leave the room, so you're not tempted to after me when you're done."

I gave a small nod in acknowledgement. Mikey grabbed a shuriken out of his belt, poking a small hole in the bag. My focus automatically shifted from my brother to the bag as the wonderful, coppery scent washed over me. It gave a wet, satisfying slosh as Mikey set it on the ground and slowly backed out the door, shutting it behind him.

Once I heard the door click closed, I surrendered to my instincts.

I pounced on the small prey, letting my fangs sink into the thin, flimsy flesh. I gave a brief shudder at the less-than-ideal cool temperature, but at this point I was too desperate for _real_ food to care. I sucked, feeling the metallic liquid slide across my tongue and down my throat.

All too soon, I had drained my prey dry. The feeding-induced haze that covered my mind lifted, but not before a twinge of disappointment ran through me that I couldn't have more. I paled at the thought, yanked the empty plastic bag from my mouth and flung it onto the floor.

However, Mikey was right. That little bit of blood was enough to dull the urge to sink my fangs into Donnie's neck to an afterthought in the back of my mind. The empty feeling in my stomach remained, but the edge had been taken off.

With my hunger—for the moment—curbed, the full weight of the night's events crashed into me full force.

I gave a big yawn, and settled into my bed.

I heard a knock as soon as I had started to drift off.

"You all done bro?" Mikey asked from the other side.

"Yeah," I said, curling up against the wall, and pulling my Space Heroes comforter closer to my chin.

Mikey took my answer as an invitation to enter. I heard the crinkle of plastic as he picked up the discarded blood bag.

" _Ar'gato, ot'to_ ," I thanked him, my voice slurring heavy with sleep.

" _Mondainai_ ," he answered simply, shutting the door behind him. " _Oyasumi, aniki_."

I surrendered to the dark, drifting into a deep slumber.

**Notes for the Chapter:**

> Yoku nemuru, otōto.- Sleep well, little brothers.
> 
> Bokken- A wooden training sword
> 
> Donnie, iki o shite.- Donnie, breath.
> 
> Watashi wa koko ni imasu.- I'm here.
> 
> Aniki- Big Brother
> 
> Ar'gato, ot'to (Arigato, otōto).- Thanks, little brother.
> 
> Mondainai- No problem
> 
> Oyasumi, aniki.- Goodnight, big brother.


	10. Chapter 10

**Summary for the Chapter:**

> With Leo asleep, the rest of the family deals with the results of Leo's, outburst in the dojo.

**Notes for the Chapter:**

> Hello, welcome back, and merry Christmas!
> 
> It's been, well, a while, and if your are still reading this after all this time I thank you for your patience!
> 
> In other thank you news, I'd like to take a moment to thank all those who've bookmarked/kudos/commented on this work so far. Whenever I go back and just look at the support you all have given this little project of mine it instantly brightens my day!
> 
> This chapter has definitely been the most difficult to write. But, I pushed though every challenge this chapter threw at me and now present to you the final product!
> 
> The characters and settings of which are owned by Nickelodeon.
> 
> Just a reminder that the Google-translate provided Japanese translations can be found at the end of the chapter.
> 
> With all of that out of the way, onto the story!

*MIKEY POV

As soon as I closed Leo’s door, I sprinted towards the dojo.

“Coast’s clear!” I whisper-yelled at my bros as I entered the dojo, just in case Leo wasn’t _quite_ asleep yet.

Though his enhanced hearing _probably_ meant that if he was awake, he could hear that too.

I _really_ needed to start thinking these things through more.

Raph looked relieved, picking Donnie up bridal-style and moving him to the infirmary, careful not to jostle his injured arm. Once they had left, I called April, letting her know to let Master Splinter know that he should come back, and that Donnie was injured.

Once the call was done, I collapsed onto the dojo floor, plastron down, all my energy completely, one-hundred percent _gone_.

I didn’t know how my bros can be so serious and calm and _leadery_ all the time, cause it’s _exhausting_.

I mean, normally Leo takes over and makes his job look like a piece of cake—which sounds _really_ good right about now—but he was busy trying _not_ to make Donnie his dinner. When Leo’s not available, Raph’ll usually step up, but he just kinda froze and then Donnie would try but Donnie...

I forced the thought from my brain.

Donnie was going to be _fine_. Raph was taking good care of him.

I, on the other hand, was still very _not_ fine.

I was _still_ tired from all the leadering I had to do and very, _very_ worried sick about my brothers.

But, at least I got to use some of my expansive comic book knowledge for once.

Thank _pizza_ I had decided—with Halloween approaching and all—that it was a good time to re-read the _Vampire Hunter_ series and the _Zombies from Outer Space_ series and the _Night of the Undead Werewolf_ series and-

 _Anyways_ , who knows what could’ve happened if I hadn’t saved us front the savage vampire-

Leo.

My _brother_.

Who’d almost...

Who could’ve...

But he didn’t-

And he would _never_ …

 _Hurt_ us.

...

_Right?_

I mean, we’re his favorite little bros, and he’s _always_ protected us, put himself in the face of danger for us, and he would _never_ lose himself, _never ever_ , not even to to some crazy new bloodsucking instinct that I’d seen consume way too many people in my comics and I _saw_ the way he attacked the bag he's losing it he's losing himself he’s gonna-

NO!

Those kinds of thoughts were _not_ going to help Leo.

Or me, for that matter.

I took a deep breath, slapping my face for good measure. Leo was fine, he’s had a little blood now so he _should_ be good for at least a little while.

Yeah.

Though I can’t imagine Donnie’ll be very happy about _where_ I grabbed the blood from.

He tends to get a _little_ touchy about certain turtles touching his stuff.

Specifically, _this_ fine, cute turtle.

“MIKEY!” Raph yelled from the infirmary, shaking me from my thoughts. “CAN I GET SOME HELP IN HERE?”

“I’LL BE THERE IN A SEC!” I yelled back. I took a few, slow deep breaths _in, out, in, out_ as I got up from the dojo floor and trudged towards the infirmary.

When I arrived, I saw Donnie laying on the medical cot with the bite stick in his mouth, a bandage around the back of his head, and with his eyes scrunched shut tight.

“Let’s get this over with before he wakes up,” Raph said from Dee’s left. “You hold him down, I’ll relocate the arm.”

I nodded and moved into position, pushing down gently on the center of Dee’s plastron and on his right arm.

“On three,” Raph started. “One two-”

A loud scream erupted from Donnie as the arm was pushed back into its socket. His body tried to buck up off the table, but I managed to keep him pinned down. A few seconds later and he went slack and silent, save for his uneven, ragged breathing.

I was pretty sure Donnie was going to be fine. Probably a little sore, but fine. We’ve all dealt with far, _far_ worse injuries before. However, I was more worried that his loud scream had woken up my newly-fanged brother.

“Go check on Leo,” Raph said, reading my mind as he started bandaging Don’s arm.

I headed out the lab door and started towards Leo’s room, but was interrupted by a brown and maroon blur that barreled past me and headed into the infirmary.

I let out a breath I didn’t know I’d been holding.

At least with Sensei here, I knew that Donnie was in good hands.

Not that Raph’s hands weren’t good hands, but-

Sensei hands were more…

Experienced.

Yeah.

That’s the word.

I quieted my steps as I approached Leo’s door. I pressed my ear-slit to the door, listing for any sign that Leo was awake.

All I heard was his near-silent, even breathing.

I let out a sigh of relief.

If Leo was sleeping, that meant that he wasn't either A; attacking any one of us to be his next main course or B; beating himself up over an instinct he didn’t really have any control over.

And well A was a practical, if not a terrifying thought, I was honestly more worried about B at the moment.

‘Cause B lead to my blue-clad brother making a bunch of really, _really_ dumb decisions—and that’s saying something coming from me—that often resulted in him falling off buildings, facing our most dangerous enemies _alone_ and ending up closer to death far more often than was comfortable for any of us.

And _because_ he had such poor decision making skills when he was beating himself up, I didn’t trust him to _not_ do something dumb like lock himself in his room or run away when we weren’t looking.

Shell, with his new abilities it’d probably _way_ easier to do something like that.

So I’d have to find some way to make sure he wasn’t left alone.

Which was easier said than done.

“Think any harder there Mikey and maybe your brain actually _will_ explode,” Raph said, and I _jumped_. “Mind sharing before it leaves in a big ball of smoke and fire?”

“Raphie!” I greeted with a voice that most definitely did _not_ crack on his name. “What’s up bro? The ceiling, New York, a flying pizza? OOH! With anchovies and jellybeans and maple syrup and sprinkles!”

Raph opened his mouth.

He closed it.

And shook his head.

“On second thought, I don’t wanna know.”

Was that a _smile_ I saw flicker across his face?

I felt warm, happy feeling bubble up inside me at making my brother amused, even for a short moment.

“Soooo, what brings you here?” I asked.

“Certainly not your pizza fantasies.”

I blew a raspberry at him.

“Two things actually,” he continued after a roll of his eyes. “One, I wanted make sure Leo’s-”

“Asleep? Yeah, he’s sleeping like the dead. Er, undead.”

“Good. Two, Donnie’s awake-”

I immediately start sprinting for the lab door, only to be stopped by a hand grabbing onto the lip of my carapace.

“And he has a concussion, so please, for the love of _pizza_ keep your Mikey-ness to like, at _most_ a five-”

“Yeah, Raph, I got it, I’ll be the carefulest turtle ever now let’s _go!_ ”

“But someone has to watch Leo-”

“And he’s sleeping hard enough he can be left alone for a few minutes and be just _fine_ let’s _go_!”

I sprinted towards the lab, dragging Raph behind me. I knew he was just going to sit in front of Leo’s door and brood for a bit, but he could do that _after_ we all said hi to Donnie while he was still awake for what would probably not be very long.

“Donnie!” I said as I rushed to give him a gentle hug—I _told_ you I’d be careful Raphie—joining him on the medical cot. “Thank goodness you're okay!”

“Good to see you too, Mikey,” he said as he brought his good arm around my shell. “Though I feel like I just got hit by a bus. What happened in there? The last thing I remember I’m hugging Leo in the dojo and the next I’m here.”

Sensei’s ears flicked forward in interest, his eye ridges arched just slightly. 

I shot Raph a nervous glance. He took a half step back and glared at me expectantly.

I turned on the puppy eyes, just a little bit thought, and Raph’s glare hardened a bit to match.

Fine, I could tell this story just fine, even _without_ backup.

Though I had to find a tactful way to do that _without_ sending Donnie on a guilt trip.

Even though literally _none_ of it was his fault.

He was almost as bad as Leo in that regard.

“From what I amazing detective skills can gather, you two were hugging under the grate and Leo threw you into the wall ‘cause the sun-”

“I’m such an _idiot_ I _knew_ the sun was rising and that-”

“ROSE AND THEN LEO TRIED TO ADMINISTER FIRST AID EXCEPT that he started to get hungry ‘cause you’re head was bleeding so I locked him in his room and _gavehimabagofRaph’sbloodsohecouldsatehimselfandnotkillanyone_ and Leo’s sleeping now but we’re all physically okay except you for obvious reasons but it’s not as bad as it could be?”

“You, huh, WHAT?!” Donnie’s incoherent spluttering cut off my nervous laugh as I shrunk into my shell a little. “I, you, blood-wait a second! Mikey, you're a genius!”

“I am? Yeah, I am! What was I a genius about again?”

“Giving Leo enough blood to sate himself before he could decide I was dinner! And using Raph’s blood specifically was genius! Raph wasn’t physically close to Leo like you were, and he wasn’t bleeding and incapacitated like I was, and then Leo wouldn’t be tempted to hurt himself to get at the remaining blood in his own body. _Arigatō, otōto!_ ”

“ _Mondaiarimasen, aniki!_ ” I responded with a smile. No need to mention that Raph’s bag was the first one I saw when I opened the fridge, so that’s the one I grabbed.

None at all.

I was a bonafide genius.

 _Donnie_ said so.

“Though,” my purple-banded brother continued, “we’re going to have to find a better solution to keep him sated, since we’ve only stockpiled a limited amount of blood and there’s only so much the three of us can safely give. If I’m able to take a look at the blood sample I took from Leo, I can see whether or not my hypothesis is correct, and can work towards finding a permanent solution to Leo’s feeding predicament.”

“Which is a problem we can solve _after_ you have had some time to rest and recover, my son,” Sensei said, gently pushing down on Donnie’s plastron as he tried to leave the medical cot.

“But that could take _days_!” he protested. “Days we might not have before… Not to mention that I _probably_ have a concussion and need to try to stay awake anyways to-”

“Stop trying to use your medical condition as an excuse to conduct science Donnie,” Raph butted in. “If it takes a few days to get you back to fighting form, you’ll take it easy for a few days even if I have to tie you to your bed and sit on your shell. ‘Sides, we all know what happened last time you tried to do science with a concussion.”

A shudder ran through all four of us as we had a collective flashback to the Explosive Cotton Candy Incident of two years ago.

“Sooooo,” I said, breaking the awkward silence. “What’s that hypothesis you had about Leo that you needed that sample for?”

Donnie’s eyes widened and his breath quickened.

“You don’t have to answer if you don’t want to, Dee,” I said quickly. “I was just trying to find a way to keep you awake like you wanted but also still let you science a bit without, y’know, explosions. I can ask something else, like… OH! Who’s your favorite _Super Robo Mecha Force Five!_ character?”

“No, it's fine, I, I was planning on telling you all after,” Donnie took a deep breath. “after I confirmed or busted my hypothesis, just so I could, hopefully, soften the blow but, when I was watching over Leo during the initial stages of his transformation, he, went into cardiac arrest and, and…”

He squeezed his eyes shut and gripped the lower sheet tightly with his fist. A few tears began to turn his mask a darker shade of purple. Sensei’s eyes went wide, and he sat down on the right side of the bed, wrapping Donnie up in a hug.

“My son,” he whispered as my genius brother sagged against him. 

“Donnie, are you, are you saying that Leo _died?!_ ” Raph said, and I felt my breath catch in my throat. “And you didn’t think to, I don’t know, _tell us_ about this?”

“Raphael!” Sensei reprimanded. “Let us give your brother a chance to explain himself.”

“ _Gomennasai._ I’m sorry I didn’t tell you, but I didn't think it was that important since Leo, since he’s still here even if he’s still-”

Donnie squeezed his eyes shut and took a deep breath to stop another sob from breaking through.

“Even if he’s still _what_ , Donnie?” Raph pressed.

“Well, technically his cells are no longer capable of functioning without support from the vampire virus, and any blood his body makes is immediately consumed to keep the virus alive, and since his blood is being used as the nutrients instead of the transportation of those nutrients, he technically doesn’t need oxygen, so he doesn’t need to breathe and he’s really only doing it out of habit and his heartbeat is very irregular and sometimes it just, stops and his body has started to stop producing the hormones that tell the bone marrow to produce blood and a majority of cellular function has ceased which means that for all intents and purposes my brother is becoming a WALKING _CORPSE_.”

Donnie’s voice had started soft, and had picked up speed and volume until, well, he exploded. Like the cotton candy in his lab that one time, leaving behind a big, emotional mess instead of delicious, sticky sugar. He sagged against Sensei, breathing heavily.

“Donnie, is Raph right?” I breathed into the heavy silence. “Is Leo really…”

A shaky nod from Donnie was all it took for my entire world to crash down around me.

My sweet, awesome, fearless big brother…

Dead.

Gone.

There’s got to be a positive in this somewhere, right?

 _Right_?

My mind came up blank.

I felt tears dampen my mask and sob escaped before I could stop it. Raph’s hands balled into tight fists and he looked seconds away from pounding the entirety of the New York underground into oblivion.

And Sensei…

Sensei looked _heartbroken_.

After a long moment, my stupid brain _finally_ came up with one somewhat positive thing about at all this.

“At least,” I tried as I sat on Dee’s other side, being careful of his injured arm as I gave him a hug, “at least we still get to have him around for a good while longer, right? I mean, it’s a better deal than most people get.”

“You are correct, _musuko,_ ” Sensei said as he squeezed Donnie just a little bit tighter “We should be thankful for the time we are still allowed to spend with Leonardo.”

“That still doesn’t change the fact that he’s _dead,_ ” Raph spat out the last word, bitterness lacing his voice.

“No, it does not,” Sensei responded simply.

“Well, when I find the vampire that did this to Leo I’m going to make him wish he had never come back from the-”

“Vengeance is a dangerous path Raphael. One I would hate to see someone else I love tread.”

Raph glared at Sensei for a moment longer, before letting out a loud growl and punching the wall on the right side of Donnie’s bed. He let his arm rest there moment before his breath hitched and he leaned forward to lean his forehead against the wall.

Sensei got up front the cot, carefully approaching Raph, placing a hand on his shoulder. Raph tensed for a moment, before relaxing at the touch and leaning into him. Sensei gently wrapped his arms around our red-banded brother.

I snuggled closer to Donnie, sniffling and _wishing_ there was some way to make this all better.

“What’s going to happen now, papa?” I asked, a voice far smaller that I wanted it to be.

“I do not know, Michelangelo,” he answered honestly. “But we will face it together. As a _family_.”

**Notes for the Chapter:**

> Arigatō, otōto!- Thanks, little brother!  
> Mondaiarimasen, aniki!- No problem, big brother!  
> Gomennasai.- I’m sorry.  
> Musuko- Son.


End file.
